Chemical Reactions Pretest

According to the law of conservation of mass, how does the mass of the products in a chemical reaction compare to the mass of the reactants?

• There is no relationship

• The mass of the reactants is greater

• The mass of the products is greater

• The masses are equal

Tags

NGSS.MS-PS1-5

How many grams of AgCl (the section marked with an x) are produced by the reaction?

• 30.0 g

• 16.0 g

• 46.0 g

• 22.0 g

Tags

NGSS.MS-PS1-5

Which of the following is a balanced equation for the synthesis of water (H₂O)?

• H₂ + O₂ → H₂O

• H₂ + 2 O₂ → 2 H₂O

• H₂ + 2 O₂ → H₂O

Tags

NGSS.MS-PS1-5

If 10 g of mercury oxide (HgO) breaks down to make 0.7 g of mercury (Hg), how much oxygen (O) will be produced?

• 17 g

• 1g

• 9.3g

• 10.7g

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

In which type of reaction does a compound break down into 2 or more simpler substances?

• synthesis

• decomposition

• single displacement

• double displacement

Sometimes two aqueous solutions can react in a double replacement reaction and produce a solid. This solid produced by liquid solutions has a specific name. What is it?

• Product

• Reactant

• Precipitate

• Isotope

What do subscripts tell you in a chemical formula?

• the number of atoms of each type of element present in a molecule

• the number of units of each substance in a reaction

• which substances are about to react

What is the name of the compound with the formula Li₂S?

• dilithium monosodium

• lithium sulfide

• lithium sulfide

• lithide sulfide

Tags

NGSS.MS-PS1-1

What can you do to correctly balance the equation?

• Add subscripts

• Add coefficients

• Add water

Tags

NGSS.MS-PS1-5

A(n) _______ chemical equation has the same number of atoms of each element on both sides of the equation.

• balanced

• unbalanced

• reactive

• incomplete

Tags

NGSS.MS-PS1-5