► Question-
Answer the following questions using the law of conservation of mass.
a) Consider a hypothetical reaction in which A and B are reactants
and C and D are products. If 15 grams of A completely reacts with
27 grams of B to produce 16 grams of C, how many grams of D will
be produced?
b) A 3.1-gram sample of sodium hydrogen carbonate is added to a
solution of acetic acid weighing 10.8 grams. The two substances
react, releasing carbon dioxide gas to the atmosphere. After the
reaction, the contents of the reaction vessel weigh 11.7 grams.
What is the mass of carbon dioxide released during the reaction?
Answers
Answer:► Question-
Answer the following questions using the law of conservation of mass.
a) Consider a hypothetical reaction in which A and B are reactants
and C and D are products. If 15 grams of A completely reacts with
27 grams of B to produce 16 grams of C, how many grams of D will
be produced?
b) A 3.1-gram sample of sodium hydrogen carbonate is added to a
solution of acetic acid weighing 10.8 grams. The two substances
react, releasing carbon dioxide gas to the atmosphere. After the
reaction, the contents of the reaction vessel weigh 11.7 grams.
What is the mass of carbon dioxide released during the reaction?
Explanation:
Which scientist established the Law of Conservation of Mass?
Joseph Proust
John Dalton
Antoine Lavoisier
Albert Einstein
2) Which one of the following is the correct statement of Law of Conservation of Mass?
Mass can neither created nor destroyed.
Atoms combined in the fixed ratio to form compounds.
In a reaction, total mass of the reactant is always greater than total mass of the products.
There is a change in mass when a chemical reaction takes place.
3) To identify the Law of Conservation of Mass, a student added 10 ml of 5% barium chloride solution into 10 ml of 5% sodium sulphate solution. Which one of the following is the correct observation?
A clear solution is formed
The solution turns to red colour
Yellow precipitate is formed
White precipitate is formed
4) In a chemical reaction, one molecule of nitrogen reacts with three molecules of hydrogen to form ammonia. If the Law of Conservation of Mass is correct, what will be the number of atoms of nitrogen and hydrogen at the end of the reaction?
N=2 , H=6
N=1 , H=3
N=6 , H=2
N=3 , H=3
5) Which one of the following combinations can a student select to prove the Law of Conservation of Mass?
BaCl2(aq) and Na2SO4 (s)
Na2SO4 (s) and BaCl2 (s)
BaCl2 (aq) and Na2SO4 (aq)
Na2SO4 (aq) and BaCl2 (s)
6) While verifying the Law of Conservation of Mass, a student added 5 g of sodium bicarbonate to a test tube containing 14.5 g acetic acid. The total mass of the reactants is 19.5 g. But the mass of the product after the reaction is only 16.2 g. The reduction in the mass of the product is due to:
Elimination of CO2 gas
Liberation of heat
Elimination of O2 gas
Elimination of CO gas
7) Which one of the following reactions is not suitable in the laboratory to verify the Law of Conservation of Mass?
Mixing HCl and NaOH solution.
Thermal decomposition of ferrous sulphate.
Mixing copper sulphate and barium chloride solutions.
Mixing lead nitrate and potassium iodide solutions.
8) In a chemical reaction, iron reacts with chlorine gas to form ferric chloride. If the Law of Conservation of Mass is correct, what is the number of Fe and Cl atoms at the beginning of the reaction?
Fe=2 , Cl=3
Fe=1 , Cl=2
Fe=2 , Cl=6
Fe = 3, Cl=4
9) Observe the following picture given below.If this reaction obeys the Law of Conservation of Mass, what will be the mass of the product?
56 g
32 g
86 g
88 g
10) To verify the Law of Conservation of Mass, barium chloride is not available. Which one of the following combinations can a student select to prove the Law?
Copper sulphate and Sodium sulphate
Sodium sulphate and sodium chloride
Copper sulphate and Sodium carbonate
Sodium sulphate and Sodium carbonate
Answer:
Explanation 1
A+B= C+D.
Mass of Reactant=Mass of products.
A=15gm
B=27gm
C=16 gm
D =26 gm (a/C TO MASS CONSERVATION)