Law of Conservation of Mass

Anthony is performing an experiment. He adds 0.25 grams of baking soda to 5 grams of water and stirs. Anthony watches as the baking soda dissolves in the water. If Anthony weighs the water and baking soda solution, what will its mass be?

• 4.75 grams
• 5.0 grams
• 5.25 grams
• 7.5 grams

If 10 grams of water are added to 5 grams of salt, how much salt water will be made?

• 2 grams
• 5 grams
• 10 grams
• 15 grams

A rock weighing 60 g is broken into 2 pieces. What are possible weights for the two pieces of rock?

• 20 g and 20 g
• 30 g and 20 g
• 30 g and 30 g
• 45 g and 10 g

Jackie creates a piece of artwork by melting crayons and mixing the colors together. She uses 10 crayons that weighed 5 grams each. What is most likely the weight of her artwork?

• 4 grams
• 20 grams
• 50 grams
• 100 grams

Leslie places 5 pounds of ice in a 1 pound bucket with a lid. The next day, she notices all the ice has melted. When she weighs the bucket with the melted ice, what will itmost likely weigh?

• 4 pounds
• 6 pounds
• 7 pounds
• 5 pounds

Thomas has 1,200 g of salt water. Which are the correct measures of salt and water before they were mixed?

• 600 g of salt and 600 g of water
• 900 g of salt and 200 g of water
• 1,200 g of salt and 1,200 g of water
• 700 g of salt and 5,000 g of water

Maria fills a bowl with 200 g of water. She puts the bowl of water in the freezer, and the water freezes. Which will most likely be the mass of the frozen water?

• 50 g
• 100 g
• 200 g
• 400 g

A student notices that an inflated balloon gets larger when it is warmed by a lamp. Which best describes the mass of the balloon as a result of this change?

• The mass of the balloon increases because the size of the balloon has increased.

• The mass of the balloon increases because the temperature of the balloon has increased.

• The mass of the balloon stays the same because the gas inside the balloon still has the same mass after it warms up.

• The mass of the balloon stays the same because warming decreases the mass enough to cancel out the effect of increasing the size.

A teacher places a penny into an amount of acid in a closed container to demonstrate a chemical change. The penny weighs 3 grams and the acid 230 grams. After the chemical reaction takes place, what will be the mass of the penny and acid?

• 3 grams

• 200 grams

• 230 grams

• 233 grams

Mrs. Godfrey wants to prove to her students that when an object is burned, its total mass is the same before and after the reaction. What should Mrs. Godfrey do to make sure this is shown by the experiment?

• burn the object in a closed container

• burn the object outside on a nice day

• add water to the object after it is burned

• split the object into two equal pieces before burning