Law of Conservation of Mass

Which chemical equation supports the Law of Conservation of Matter?

• 2H + O2 → 2H2O

• H2 + O2 → H2O

• H2 + O2 → 2H2O

• 2H2 + O2 → 2H2O

Tags

NGSS.MS-PS1-5

Alexandra is performing this combustion reaction in lab: C H + 5O → 3CO + 4H O. If she carefully measures out 220 g of C H and discovers that she has produced 660 grams of carbon dioxide and 360 g of water, how many grams of oxygen must have been required to react with the C H ?

• 220 grams

• 580 grams

• 800 grams

• 1240 grams

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A chemical reaction in which all of the reactants and products are gases takes place in a closed system. How would the chemical equation for that reaction be described?

• The mass of the product gases is equal to the mass of the reactant gases.

• The mass of the product gases is greater than the mass of the reactant gases

• The mass of the reactant and product gases will vary with the temperature.

• The mass of the reactant gases is greater than the mass of the product gases.

Tags

NGSS.MS-PS1-5

A substance has one atom of sodium and one atom of chlorine. What is the chemical symbol for the element?

• NaCl

• H2O

• O2

• N2

Tags

NGSS.MS-PS1-1

The mass of chemical A is 2 g, and the mass of chemical B is 5 g. If the two chemicals are mixed and a chemical reaction takes place, what is the mass of the end products?

• 2 grams

• 3 grams

• 7 grams

• 10 grams

Tags

NGSS.MS-PS1-5

The chemical formula for ammonia is NH3 . What composes this compound?

• 1 sodium and 3 helium atoms

• 3 sodium and 3 hydrogen atoms

• 3 nitrogen and 3 helium atoms

• 1 nitrogen and 3 hydrogen atoms

Tags

NGSS.MS-PS1-1

How is the Law of Conservation of Matter best represented in a chemical reaction?

• A The mass of the products is greater than the mass of the reactants.

• B The mass of the reactants is greater than the mass of the products.

• C The mass of the reactants is equivalent to the mass of the products.

• D The mass of the reactants has no relationship to the mass of the products.

Tags

NGSS.MS-PS1-5

Which chemical equation is balanced to show that matter is conserved during the reaction?

• CaCO3 → CaCO2 + CO2

• C + H2O → CO + H2

• N2 + 3H2 → 3NH3

• SO2 + O2 → 2SO4

Tags

NGSS.MS-PS1-5

Which chemical equation is balanced to show that mass is conserved during the reaction?

• H + Cl → HCl

• H2 + O2   → H2O

• H + Cl → 2HCl

• H2 + O2 → 2H2O

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

How many atoms are found in 9 molecules of nitrogen gas?

• 7

• 9

• 11

• 18

Tags

NGSS.MS-PS1-1