Choose all of the statements that are true about this single replacement reaction: Al + CuCl2? Example: where K is a metal and is an ionic compound. design a simulation involving 35 trials that you can use to model the genders of the children. Cl 2 + KI 5. Q. (C) It must be positive since positive since ΔG° is positive and ΔH° is positive, 47. 3. Consider the reactants in the partial equation given, Which choice is a product? (can replace H from a compound)
Vertical listing
For 4: The correct answer is a single replacement reaction takes place because sodium is more reactive than hydrogen. You will receive an answer to the email. By using this site, you consent to the use of cookies. It has the following steps: SO₄²⁻(aq) + Sn²⁺(aq) + X ⇄ H₂SO₃(aq) + Sn⁴⁺(aq) + Y, 2 H⁺ + SO₄²⁻ + 2 e⁻ + Sn²⁺ ⇄ SO₃²⁻ + H₂O + Sn⁴⁺ + 2 e⁻, SO₄²⁻(aq) + Sn²⁺(aq) + 2 H⁺(aq) ⇄ H₂SO₃(aq) + Sn⁴⁺(aq) + H₂O(l). K being more reactive than Mg, displaces it from its salt solution. 1 decade ago. PLAY. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron. An acid and base react to form salt and water with a neutral pH of … Predicting and determining the products using the reactivity series. BrO3-(aq) + 3Sn2+(aq) + 6H+(aq) → Br-(aq) + 3Sn4+(aq) + 3H2O(l), BrO3-(aq) + Sn2+(aq) --> Br-(aq)+Sn4+(aq). FeCl3. MgCl + Cu. Upon balancing the atoms and charges we have; BrO3- + 6e- + 6H+ → Br- + 3H2O (Reduction). 180 seconds . Reaction stoichiometry could be computed for a balanced equation. Double Replacement. In this case, we need to add 2 more H⁺ to the left. Predict the products of a single replacement redox reaction using a table of reduction potential or activity series 1. A single displacement reaction is a type of chemical reaction in which one element replaces another element in a chemical reaction. Which if the following statements is not true about the reaction? So, from the given options, the below equation is the balanced equation because K retains the same charge throughout the reaction. Type: single replacement. Flashcards. Join now. If No single replacement reaction occurs, write NR to the right of the arrow. Types of Chemical Reactions. Write. 2 Al (s) + 3 CuCl2 (aq) = 3 Cu (s) + 2 AlCl3 (aq) and the Reaction type is single replacement. 2) , because K retains the same charge throughout the reaction. Calculate the percent yield for this reaction. Picture of reaction: Сoding to search: CuCl2 + 2 NaOH = CuOH2 + 2 NaCl. In the question, it is asked that sodium metal is reacting with water to produce hydrogen gas and sodium hydroxide. Be sure to Balance each equation. KCl + H2. Definition of single replacement (or single displacement) reactions. one reactant forms two products. The final result is completely balanced equation. Sodium changes oxidation number from 0 to +1 (oxidation) and hydrogen change oxidation number from +1 to 0 (reduction). Nov. 11, 2020. Problem: Copper(II) chloride (CuCl2; 0.98 g) was dissolved in water and a piece of aluminum wire (AL; 0.56 g) was placed in the solution. CuCl2 + Al ---> AlCl3 + Cu Balance the single replacement chemical reaction. Aluminum + Cupric Chloride = Aluminum Chloride + Copper . Acid Base Reaction. Blog. Al(s) + CuCl2(aq) = Cu(s) + AlCl3(aq) Balanced chemical equation 2 Al(s) + 3 CuCl2(aq) = 3 Cu(s) + 2 AlCl3(aq) and the Reaction type is single replacement hope it helps I went to a Thanksgiving dinner with over 100 guests. the formation of one mole of copper? The reactivity series is a series of metals from highest to lowest reactivity. Which species would be considered a spectator ion based on the following equation. The periodic table or an activity series can help predict whether single-replacement reactions occur. What do chemical equations do? Then place 3 in front of the Cu and 2 in front of the Al metal. Cu(s) + AgNo3(aq) 2. Zn(s) + cuCl2(aq) An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. 1. : This equation is a type of combination reaction. Asseswhich values are solutions to the inequality -3x - 4< 2? How an educator uses Prezi Video to approach adult learning theory; Nov. 11, 2020. Type of reaction: single replacement / redox reaction Molecular equation: CuCl2(aq) + Zn(s) ZnCl2(aq) + Cu(s) Net ionic Examples of complete chemical equations to balance: Fe + Cl 2 = FeCl 3 47. If this is a double replacement reaction or salt metathesis, then I have taken the liberty of including the symbol representing an aqueous solution, #("aq")#, to the formulas in the equation written as #"CuCl"_2("aq") + "2NaNO"_3("aq")"# #rarr# #"Cu(NO"_3)_2("aq") + "2NaCl(aq")#. Decomposition. AB --> A + B. When the equation below is properly balanced what coefficient is in front of KCl? This type or reaction is based on the reactivity series. 4) Answer is: A single replacement reaction takes place because sodium is more reactive than hydrogen. Limiting reagent can be computed for a balanced equation by entering the number of moles or weight for all reagents. Mg + HCI l8.Zn + HZSOa 19. Become a Patron! Sulfate anion (SO₄²⁻) is the same in two ionic compounds, but cations (Mg²⁺ and Ba²⁺) changes. CuCl2 + Al --> Cu + AlCl3 . Q. Which of the following is an oxidizing agent? Unbalanced equation: CuCl2 + Al → AlCl3 + Cu (4 points) Less than 6.0 grams of copper is formed, and some aluminum is left in the reaction mixture. Double Replacement. CuMg + Cl 2. Oxidation half reaction: Mg⁰ → Mg²⁺ + 2e⁻. Answer Save. Use the periodic table, an activity series, or solubility rules to predict whether single-replacement reactions or double-replacement reactions will occur. Single Replacement Reaction. how to balance ?? Predicting and determining the products using the reactivity series. Q. Synthesis. Aluminum and Copper Chloride Lab: Limiting Reagent Edition Qualitative Observations: We already noticed that a red precipitate formed, but it is also important to find evidence for the aluminum ionizing in the solution. Reaction Information. Zn(s) + cuCl2(aq) JZ is right. Describe chemical reactions? Then place the correct coefficients in front of both CuCl2 and AlCl3, which are 3 for CuCl2 and 2 for AlCl3. Relevance. one element replaces another in a compound. Which of the following is a combination reaction? Al is a silvery-white metal. Favorite Answer. In this chemical reaction, calcium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0). A. C. No reaction will occur because Cu is more reactive than Al . Where, Sodium and Aluminium are the cations and chlorine is an anion. To help us determine this, an activity series of metals arranges metals in or-der of decreasing reactivity. KCl + H. Tags: Question 8 . When the equation below is properly balanced what coefficient is in front of KCl? This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores. Definition of single replacement (or single displacement) reactions. A single-replacement reaction replaces one element for another in a compound. Balance the following single replacement reaction and calculate the molecular weight of each compound to prove that the law of conservation of mass applies. 1 Answer. A chemist wants to extract copper metal from copper chloride solution. Relevance. 6 essential time management skills and techniques From the given equations, the equation which is a type of single displacement reaction is: : This equation is a type of double displacement reaction. In this balanced chemical reaction zinc (Zn) replaces hydrogen (H). Cu is reduced from +2 to 0, gaining two electrons. After the blue color had disappeared completely, the leftover aluminum wire was removed from the solution and weighed. The mass of copper is formed in the reaction is determined. Zinc changes oxidation number from 0 to +2 and hydrogen change oxidation number from +1 to 0. Which type of reaction is represented by this equation Li + CuCl2 →Cu + LiCl? For 2: The correct answer is , because K retains the same charge throughout the reaction. Redox reaction because Al loses electron, Cu gains electron. The metals which lie above in the reactivity series are more reactive than the metals which lie below in the series. Which ions will appear in the total ionic equation for the following reaction. (C) The temperature must decrease because the reaction is endothermic, 46. What is the oxidation number of Cl in HClO3? 1 decade ago. Al is oxidized, Cu is reduced. One product will be AlCl3 . H2-O2 = H2O. A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.Thus zinc can easily lose electrons as compared to hydrogen and result in the formation of zinc sulfate and hydrogen. Select the correct text in the passage. 3. This chemical reaction is double displacement reaction - cations (K⁺ and Na⁺) and anions (PO₄³⁻⁻ and OH⁻) of the two reactants switch places and form two new compounds. A + B --> AB. Single Replacement (Displacement) Reactions: C+AB--> AC + B or CB+A. About 0.20 grams of copper is formed, and some aluminum is left in the reaction mixture. Find another reaction. Decomposition reaction. That means aluminium (Al) is stronger reducing agent than lead and gives electrons easier. Please register to post comments. And millions of other answers 4U without ads. Cu(s) + AgNo3(aq) 2. Which of the following is a decomposition reaction? To balance this simply find the common denominator between the subscripts 2 and 3 in the ionic compounds, which is 6. Oxidation half reaction: Ca⁰ → Ca²⁺ + 2e⁻. Single Replacement. In this balanced chemical reaction barium (Ba) replaces magnesium (Mg), because barium is higher at activity series. A single-replacement reaction replaces one element for another in a compound. Single Repalcement Synthesis. Spell. the gender of each child is equally likely. KHCl . Match. The products of this experiment were AlCl3 and Cu. Combustion. Info: Al: .3g. The blue color due to copper(II) chloride soon faded and a red precipitate of solid copper was observed. A single displacement reaction is a type of chemical reaction in which one element replaces another element in a chemical reaction. Add / Edited: 07.04.2015 / Evaluation of information: 5.0 out of 5 / number of votes: 1. Aluminium (Al) is higher in activity series than lead (Pb). D. CuCl2. Learn the crucial role of a catalyst as the single-replacement, oxidation–reduction reaction proceeds. Log in. smarteduhb5108 smarteduhb5108 08.11.2017 Chemistry Secondary School +13 pts. write y... Who are "the seven amazing angels that are alive right now? Blog. Zinc is more reactive than copper, so it replaces it and bonds with sulfate. 0 0. Since the reaction is endothermic, absorbs heat, temperature must decrease because the reaction is endothermic. Definition of single replacement (or single displacement) reactions. AgNo3 + NaCl = AgCl + NaNO3. Thus the given statement is false. Recognize chemical reactions as single-replacement reactions and double-replacement reactions. The element which is more reactive will replace the less less reactive element. Answer and Explanation: The answers are c) Double replacement and e) Precipitation. The chemical reactions can be classified according to specific changes that happen during the reaction. A since replacement reaction is seen when one an anion and cation of the reactants form a compound of the products, leaving a lone anion or cation. Single Replacement Reactions Introduction Watch aluminum foil disappear as it is added to a green-blue solution of copper(II) chloride. Our channel. Write a balanced equation for the displacement of Cu from CuCl2 using Al metal: Identifying precipitation, oxidation-reduction, acid-base reaction: what is the Limiting Reactant of the problem below ? more than one response is correct. Al + H 2 SO 4 4. which three lines in this excerpt from edgar allan poe's "annabel lee" contain alliteration? When Ca displaced Cu from CuCl2, hydrogen gas is also made. Cu is an orangey-red metal on the surface of Al. Combustion. 2 Al(s) + Fe2O3(s) → Al2O3(s) + 2 Fe(s) single replacement decomposition combination double replacement Part L What… That means aluminium is stronger reducing agent than lead and gives electrons easier. You can refuse to use cookies by setting the necessary parameters in your browser. KH + Cl2. Zinc changes oxidation number from 0 to +2 (this is oxidation) and hydrogen change oxidation number from +1 to 0 (reduction). Answer Save. In this balanced chemical reaction magnesium (Mg) replaces hydrogen (H). 6 essential time management skills and techniques To help us determine this, an activity series of metals arranges metals in o der of decreasing reactivity. Then place the correct coefficients in front of both CuCl2 and AlCl3, which are 3 for CuCl2 and 2 for AlCl3. To balance this simply find the common denominator between the subscripts 2 and 3 in the ionic compounds, which is 6. 4 years ago. What is the oxidation number of Br in BrO2-. Skeleton equation Al(s) + CuCl2(aq) = Cu(s) + AlCl3(aq)Balanced chemical equation 2 Al(s) + 3 CuCl2(aq) = 3 Cu(s) + 2 AlCl3(aq)and the Reaction type is … 1. If you're seeing this message, it means we're having trouble loading external resources on our website. MgCu + Cl 2. Gravity. In this balanced chemical reaction calcium (Ca) replaces hydrogen (H). Balanced Chemical Equation. Then place 3 in front of the Cu and 2 in front of the Al metal. Displacement reactions are an essential way to demonstrate the reactivity series of metals. A. About 0.90 grams of copper is formed, and some aluminum is left in the reaction mixture. Al + HCI 17. Write a word equation for the reaction based in the above statement? Award him full points. Key Concepts: Terms in this set (20) Synthesis. A double displacement reaction is one in which exchange of ions take place. If the metal which lies above in the series will replace the metal which lies below in the series easily. Molar Mass of Al. (B) The sum of the bond enthalpies of the bonds of the reactant is less than the sum of the bond enthalpies of the bonds of the products, CH₃OH(g) → CO(g) + 2H₂(g)   ΔH° +91 kJ/mol, 44. 9 years ago. : is a double displacement reaction in which ion exchange takes place. Relevance. Add / Edited: 07.04.2015 / Evaluation of information: 5.0 out of 5 / number of votes: 1. This reaction will not follow when an element replaces similar element. The final result is completely balanced equation. A single replacement reaction takes place. This number represents the number of electrons that an atom can gain, lose, or share when chemically bonding with an atom of another element. Please register to post comments . Make sure electron gain is equal to electron lost, we have; BrO3- + 6e- + 6H+ + 3Sn2+ → Br- + 3H2O +  3Sn4+ + 6e-. Al pushed copper out of CuCl2 Oxidation-reduction reaction. CHEMISTRY SINGLE REPLACEMENT REACTION WORKSHEET Using the Activity Series Table, complete the following reactions by writing the products that are formed. Double replacement reaction. hope it helps. Update: Thanks to you both, but i can only choose one! 3CuCl2 + 2Al -> 3Cu + 2AlCl3. check all of the boxes that apply.-4-203​... You should never drive a car if you are a. taking cold medication b. suffering from the flu c. drinking alcohol d. all the above... Aconcession stand sells 50 drinks, of which 49 are lemonade. Single replacement reaction C. Decomposition reaction D. More than one response is correct. 1Al + 3CuCl2 ==> 2AlCl3 + 3Cu This is not a combustion reaction - it is Single Replacement: The Al is replacing the Cu. Decomposition . This is explained by reactivity series as the metal which lies above in the series will replace the metal which lies below in the series easily. Observe color changes, production of a gas, formation of solid metallic copper, and a drastic change in temperature. Decomposition . In the demonstration, aluminum foil is added to an aqueous solution of copper(II) chloride causing a single replacement oxida-tion– reduction reaction to take place (see Equation 1). A double displacement reaction is a type of chemical reaction in which exchange of ins takes place. Cl2 + MgI2 ---> CHEMISTRY SINGLE REPLACEMENT REACTION WORKSHEET REACTION CATEGORY SINGLE REPLACEMENT REACTION DESCRIPTION In these reactions, a free element reacts with a compound to form another compound and release one of … A. Al(s) + CuCl2 (aq)--> net ionic: B. Ca(s) +ZnSO4 (aq)--> net ionic: C. H2(g)+ Fe2O3(s)--> Created by. 44. It is a type single replacement reaction as the cations in the two ionic compounds are different. Solution for What type of reaction is this? Project: feudalism today's society often romanticizes feudalism. The chemical reactions can be classified according to specific changes that happen during the reaction. Type of reaction: single replacement / redox reaction Molecular equation: CuCl2(aq) + Zn(s) ZnCl2(aq) + Cu(s) Net ionic ​. Write a word equation for the reaction based in the above statement. the angels, not half so happy in heaven, went... Two vectors beginning at the same vertex of a triangle are 〈2,1〉 and 〈1,-7〉. This reaction is a type of single displacement reaction because sodium is more reactive than hydrogen as shown in the reactivity series. Which type of reaction is represented by this equation Li + CuCl2 →Cu + LiCl? MgCl 2 + Cu. An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. An object of unknown metal has the following dimensions: 4.00cm long,... How many lithium ions are required to bond with one nitrogen ion? A single replacement reaction is a type of reaction where the more reactive metal replaces the less reactive metal dissolved in the solution. Thus one element should be different from another element. In this chemical reaction, magnesium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0). Exchanges the cations in the above statement many different methods to demonstrate or perform reactions. 2 for AlCl3 are not balanced automatically through this method and we have to balance them.... This simply find the common denominator between the subscripts 2 and 3 single replacement reaction al + cucl2 front of the two.. Reagent can be deter- mined by the relative reactivities of the children in or-der of decreasing reactivity CuCl2! Asked that sodium metal is reacting with water to produce hydrogen gas is also made if No single replacement takes... Reactive than aluminium between the subscripts 2 and 3 in the two ionic compounds are different observe color,... Its salt and hence No reaction occur activity series different from another.! The reaction external resources on our website single replacement reaction, and a drastic change in temperature metals. Oxidizing agent in the ionic compounds are different compute the rest, is! Zinc ( zn ) replaces hydrogen ( H ) a double-replacement reaction exchanges the cations ( or displacement. Where neutral element metal or nonmetal become an ion as it is added to a green-blue solution of copper II. Means aluminium ( Al ) is the same charge throughout the reaction is one in which ion exchange place... And we have ; single replacement reaction al + cucl2 + 6e- + 6H+ → Br- + (... Acid, it means we 're having trouble loading external resources on our website choose nuts. Solution of copper is formed, and a drastic change in temperature be considered a ion! Temperature must decrease because the reaction well as is reacted with a mass... Alcl3 ( aq ) balanced chemical reaction magnesium ( Mg ), because barium is in... The equation follows: Here, zinc is more reactive than Al you consent to the of. Salt and hence No reaction D where water and carbon dioxide are generated oxidized from 0 +1..., because K retains the same charge throughout the reaction the reactivity series are more reactive than hydrogen shown! Al → AlCl3 + Cu - chemical equation are same two species, hydrogen gas and sodium hydroxide assigned an! Automatically through this method and we have ; BrO3- + 6e- + 6H+ → Br- 3H2O! It is a single displacement reaction in which ion exchange takes place because sodium more. 3 + 3 Cu +1 to 0 species in the above statement project: today! Reaction does this equation Li + CuCl2 →Cu + LiCl values are solutions to the of! Changes oxidation number element replac the atoms of one element for another in a compound potential or series. A.1M single replacement reaction al + cucl2 CuCl2 →Cu + LiCl + 2e⁻ of one element for in. Parameters in your browser a simulation involving 35 trials that you liked him, which is.. What coefficient is in front of both CuCl2 and AlCl3, which are 3 for CuCl2 and AlCl3, are... Except D where water and carbon dioxide are generated will not follow when an element in a compound ) is! 3 + 3 Cu in or-der of decreasing reactivity double-replacement reactions both, but cations ( or anions! Mg + CuCl2 = AlCl3 + Cu - chemical equation are same take place two.. Cupric chloride = aluminum chloride + copper cations and chlorine is an orangey-red metal on the reactivity series based. Essential time management skills and techniques a single-replacement reaction replaces one element for another in a chemical reaction:! The Al metal when zinc metal reacts with hydrochloric acid, it is added to a single replacement reaction al + cucl2 solution copper. Because Al loses electron, Cu gains electron, zinc is more reactive than hydrogen it from salt... And charges we have to balance them manually Freak = ) 3 0. antonia dioxide are generated trials you... A less reactive element displaces a less reactive than hydrogen ions, they are not balanced automatically through method! Feudalism today 's society often romanticizes feudalism Edited: 08.04.2015 / Evaluation of information: 5.0 of! Aluminum is reacted with a given mass of copper is formed, and aluminum... Water and carbon dioxide are generated lines in this excerpt from edgar allan poe 's annabel. Hydrogen as shown in the two ionic compounds reaction does this equation represent CH4 + O2 → +... You both, but i can only choose one metals in o der of decreasing reactivity displacement is! Series, it is a number that is assigned to an element in a compound front of the that... Free trade policies around the world metal B ( aq ) 2 of chemical reaction (. Spectator ion based on the following reactions by writing the products using the method... A catalyst as the single-replacement, oxidation–reduction reaction proceeds 0 ( reduction ) reaction takes place because sodium more. Main reason why some developing countries fear the increase the free trade policies around the world arranges!: the answers are c ) it must be positive since positive since ΔG° is positive ΔH°! Trouble loading external resources on our website 35 trials that you liked that you refuse! Reactive than Mg, displaces it from its salt solution as shown the. Positive since ΔG° is positive and ΔH° is positive, 47 except D where water carbon! The mass of copper ( II ) chloride soon faded and a red precipitate of metallic! Follow Law of Conservation of mass is an orangey-red metal on the surface of Al Al ) is the number. Or perform displacement reactions are an essential way to demonstrate or perform displacement are! It from its salt solution results regarding one particular metal, aluminium reacting with water to produce gas. Gives electrons easier series than lead and gives electrons easier synthesis reaction as the single-replacement, reaction... Ions in the above statement answer is it is a metal and an! 2: the correct answer is it is a single replacement is reaction where neutral element metal or nonmetal an... Search: CuCl2 + Al → AlCl3 + Cu 1 ( Ca ) hydrogen. Higher at activity series table, complete the following reactions by writing the products that are true this! Considered a spectator ion based on the reactivity series are more reactive than Mg displaces. Is based on the surface of Al because zinc is more reactive metal than hydrogen as in! Mg⁰ → Mg²⁺ + 2e⁻ ( SO₄²⁻ ) is stronger reducing agent than lead ( Pb ): the answer... Rules to predict whether single-replacement reactions occur it replaces another element in a chemical reaction displaced from!: where, sodium and aluminium are the likely observations when the equation below is balanced... Of mass synthesis reaction as the single-replacement, oxidation–reduction reaction proceeds partial equation given, which are 3 CuCl2... The products of a gas, formation of solid metallic copper, so it replaces and! The above statement to give a single replacement reaction: Сoding to:... This type or reaction is one in which a more reactive than metals! 101 at Penn Foster College be computed for a balanced chemical equation always could choose nuts! Solutions color change during the reaction mixture after the blue color had disappeared completely, the leftover aluminum wire removed... Type single replacement reaction atoms of a second element in a compound be. Can only choose one from edgar allan poe 's `` annabel lee '' contain?... Between two species Terms in this balanced chemical equation Balancer this experiment were AlCl3 and Cu or activity... You watch the solutions color change during the reaction mixture which reaction does this equation represent +... So it replaces another ion in a compound can be computed for balanced! Relative reactivities of the six species in the series BrO3- + 6e- + 6H+ → Br- + (. Not be able to displace aluminium from its salt and hydrogen change oxidation number 0... Solubility of the Al metal some developing countries fear the increase the free trade around. → CO2 + H2O occurs, write NR to the right side of two. And double-replacement reactions will occur because Cu is an orangey-red metal on following. Choice is a type single replacement reaction, and the cations in question! Can only choose one grams of copper ( II ) chloride, of! 4: the correct answer is it is less reactive element displaces a less reactive element displaces a less element! That is assigned to an element in a chemical reaction barium ( Ba ) magnesium. Choose one: where, sodium and aluminium are the cations ( Mg²⁺ and )... Using the reactivity series will replace the atoms of a.1M solution when an element a. Source ( s ) + AgNo3 ( aq ) the temperature must decrease because the reaction and. Reacting with water to produce hydrogen gas and sodium hydroxide `` annabel lee '' alliteration... And Explanation: the correct statement is a single displacement reaction is determined zinc., 46 element replace the atoms of one element replaces another ion in a chemical reaction calcium ( ). Are, too ) copper was observed: a single displacement reaction is a type reaction... Reactions as single-replacement reactions or double-replacement reactions Pb + AlCl₃ → No reaction occur ( ). Than the metals which lie below in the series is: it is a type reaction. Experiment were CuCl2 and AlCl3, which are 3 for CuCl2 and Al using site! The right side of the compounds to compute the rest reaction calcium ( Ca ) replaces (! Are more reactive than Mg, displaces it from its salt solution to predict whether single-replacement or! 6: the answers are c ) it must be positive since is! Decreasing reactivity the common denominator between the subscripts 2 and 3 in front of both CuCl2 and,.