Mass Conversion

Convert 50.0 grams of H₂O to moles of H₂O.

• 901 moles

• 18.02 moles

• 2.77 moles

What mass of calcium chlorate, Ca(ClO₃)₂, is equivalent to 0.750 moles of the substance?

• 155.24 grams

• 206.98 grams

• 128.65 grams

2.50 moles of sodium sulfate, Na₂SO₄, are added to a solution. What mass of the substance was this?

• 297.65 grams

• 142.05 grams

• 355.13 grams

3.0 moles of sodium hydroxide, NaOH, is equal to what mass?

• about 40 grams

• about 23 grams

• about 120 grams

When converting a mass to moles, what unit must be in the denominator of the conversion factor?

• grams

• moles

• grams/mole

Convert 13.25 grams of magnesium nitrate, Mg(NO₃)₂, to moles of the substance.

• 0.100 mole

• 0.0986 mole

• 0.0893 mole

176 grams of carbon dioxide, CO₂, is equal to how many moles of the substance.

• about 44 moles

• about 4 moles

• about 1 mole

When converting a moles to mass, what unit must be in the denominator of the conversion factor?

• grams

• moles

• grams/mole

If a reaction starts with a total 75g of reactants it should produce 

• a total of 40g of products

• a total of 75g of products

• a total of 180 g of products

• None of the above

Tags

NGSS.HS-PS1-7

The Law of Conservation of Mass states that mass is neither created nor destroyed in an ordinary chemical reaction. When an iron nail rusts, it seems to get heavier in mass. Does the iron nail follow the Law of Conservation of Mass?

• No, rusting is an exception to the Law of Conservation of Mass.

• No, since rusting is a chemical change it does not follow the Law of Conservation of Mass.

• Yes, the iron rearranges its protons so that the masses are the same before and after the reaction and rusting follows the Law of Conservation of Mass.

• Yes, iron chemically combines with the oxygen in the air so if you add the oxygen into the mass of the chemicals before the reaction, the mass after the reaction is the same.

Tags

NGSS.HS-PS1-7