This Grade 5 conservation of mass worksheet challenges fifth graders to apply the law that matter is neither created nor destroyed during chemical reactions. Students complete fill-in-the-blanks calculating reactant and product masses, work with vocabulary like reactant, product, and conserved, and complete a matching activity. They learn why burning wood seems to lose mass and how sealed containers reveal that total mass always stays equal during chemical changes.
Style:
Chemical and Physical Changes
Part A: Fill in the Blank
Write the missing word or number on each line.
1. If 16 grams of one reactant combines with 8 grams of another, the products will weigh 24 grams total.
2. A starting substance in a chemical reaction is called a reactant, while the substance formed is called a product.
3. If 50 grams of vinegar reacts with 5 grams of baking soda in a sealed bag, the bag still weighs 55 grams.
4. When wood burns in an open fire, the ash weighs less because gases like carbon dioxide escape into the air.
5. The new substance formed during a chemical reaction is called a product of that reaction.
6. If 10 grams of hydrogen reacts with 80 grams of oxygen to form water, the water weighs 90 grams.
7. Mass is neither created nor destroyed; it is conserved during any chemical reaction.
8. When iron rusts, it gains mass because oxygen from the air joins with the iron to form iron oxide.
9. If 12 grams of carbon burns completely with 32 grams of oxygen, the product weighs exactly 44 grams.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Total mass of 5g + 7g reactants
→ 12 grams
Reactant
Word for starting materials
→ Reactant
12 grams
Word for new substances formed
→ Product
Conservation
Mass law during reactions
→ Conservation
Product
Chemical and Physical Changes
★ Part A: Fill in the Blank
Write the missing word or number on each line.
1) If 16 grams of one reactant combines with 8 grams of another, the products will weigh 24 grams total.
2) A starting substance in a chemical reaction is called a reactant, while the substance formed is called a product.
3) If 50 grams of vinegar reacts with 5 grams of baking soda in a sealed bag, the bag still weighs 55 grams.
4) When wood burns in an open fire, the ash weighs less because gases like carbon dioxide escape into the air.
5) The new substance formed during a chemical reaction is called a product of that reaction.
6) If 10 grams of hydrogen reacts with 80 grams of oxygen to form water, the water weighs 90 grams.
7) Mass is neither created nor destroyed; it is conserved during any chemical reaction.
8) When iron rusts, it gains mass because oxygen from the air joins with the iron to form iron oxide.
9) If 12 grams of carbon burns completely with 32 grams of oxygen, the product weighs exactly 44 grams.
★ Part B: Matching
Match each item on the left to the correct answer on the right.
1) Match each item to its correct answer.
Total mass of 5g + 7g reactants
→ 12 grams
Reactant
Word for starting materials
→ Reactant
12 grams
Word for new substances formed
→ Product
Conservation
Mass law during reactions
→ Conservation
Product
Ready to Practice?
Complete each section carefully.
10 Questions
10-15 minutes
Auto-graded
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