4.2 Law of Conservation of Mass
A reaction of heating calcium carbonate produces calcium oxide and carbon dioxide gas. Heat 10.0 g calcium carbonate until no more carbon dioxide gas is given off. The remaining material has a mass of 5.6 g. What mass of carbon dioxide gas was produced in the reaction? ___ g
4.4
A reaction between ammonia gas and chlorine gas produces ammonium chloride and nitrogen gas. A reaction of 17.0 g of ammonia with 26.6 g of chlorine gas gives off 3.5 g of nitrogen. What mass of ammonium chloride is formed in the reaction? ___ g
40.1
What is an element?
A substance that cannot be broken down into a simpler substance by ordinary chemical means
In addition to ash, what is produced when wood burns?
Carbon dioxide and water vapor
Mass is conserved in physical but not chemical changes in matter.
FALSE
A reaction of heating potassium permangante produces potassium manganate, manganese dioxide and oxygen gas. Heat 15.8 g potassium permangante until no more oxygen gas is given off. The remaining material has a mass of 14.2 g. What mass of oxygen gas was produced in the reaction? ___ g
1.6
A reaction of 12.640 g of copper oxide with 0.316 g hydrogen produces 2.844 g of water and X g of copper. X = ___ g
10.112
When heated, calcium hydroxide and ammonium chloride react to produce ammonia gas, water vapor, and solid calcium chloride. Suppose 5.00g of calcium hydroxide and 10.00g of ammonium chloride are mixed in a test tube and heated until no more ammonia is given off. The remaining material in the test tube has a mass of 1.27 g. What is the total mass of ammonia and water vapor produced? ___ g
13.73
According to the law of conservation of mass, if an atom of element A has a mass of 2 units, while an atom of element B has a mass of 5 units, what would be the mass of the compound A3B2?
16 units
2.56 g of hydrogen reacts completely with 20.32 g of oxygen to form X g of water. X = ___g
22.88
A reaction of 22.85 g of sodium hydroxide with 20.82 g of hydrogen chloride produces 10.29 g of water and X g of sodium chloride. X= ___ g
33.38
Calcium carbonate, CaCO3, decomposes when heated to calcium oxide (CaO) and carbon dioxide (CO2). If 100 g of calcium carbonate is allowed to decompose, 56 g of calcium oxide is produced. What mass of carbon dioxide is produced by the decomposition? _____ g
44
Magnesium (24.48 g) reacts with hydrochloric acid (X g) to produce hydrogen gas (2.04 g) and magnesium chloride (96.90 g). How much hydrogen chloride was used in the reaction? X = ___ g
74.46
During a chemical reaction, the law of _____ _____ states that the total mass of the products must be equal to the total mass of the reactant.
Conservation of mass
During a chemical reaction, the total mass of the products must be equal to the total mass of the reactants is states by the law of _______.
Conservation of mass
The law of conservation of mass states that in conventional chemical reactions matter can not be ___ or destroyed, only rearranged.
Created
For any chemical process in an isolated system, the mass of reactants must be ____ the mass of products.
Equal to
In any chemical reaction or physical change, the mass of the products is ___ the mass of the reactants.
Equal to
According to conservation of mass when water freezes into ice the amount of mass of the ice would...
Equal to that of the water
Matter is not conserved in chemical reactions.
FALSE
When one or more substances undergo a chemical reaction, the:
Mass of the product and reactant remains the same
When one or more substances undergo a chemical reaction, the:
Mass of the product and the reactant remains the same
According to the law of conservation of mass, mass is always conserved in a chemical reaction.
TRUE
Lavoisier discovered the principle of conservation of mass in chemical reactions.
TRUE
Mass is always conserved in chemical reactions.
TRUE
The products of a chemical reaction can never have greater mass than the reactants.
TRUE
What does the law of conservation of mass state?
That during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants. In other words, mass cannot be created or destroyed during a chemical reaction, but is always conserved.
