Category 1 Pre-assessment

An equation for a chemical reaction is shown. Which statement provides evidence that mass is conserved in the reaction?

• Two new substances are formed in the products

• Water is one of the products, but one of the reactants

• two hydrogen atoms are in the reactants, and two hydrogen atoms are in the products

• 1 chlorine atom pairs with the 1 sodium atom in the products, and 1 chlorine atom pairs with one hydrogen atom in the reactants

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A chemical equation for the reaction between calcium hydroxide, Ca(OH)₂, and sulfuric acid, H₂SO₄, is shown. The masses of some of the reactants and products are given in grams. How many grams of sulfuric acid were used in the reactions?

• 62 g

• 98 g

• 36 g

• 100 g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement describes an action that most likely resulted in a chemical reaction?

• a pan of water was heated on a stove, and steam formed

• a liquid was mixed with another liquid, and a precipitate formed

• a liquid was sprayed into the air, and a sweet odor was smelled

• a child blew through a wand filled with soap and bubbles were produced

Tags

NGSS.MS-PS1-2

A compound secreted by honeybees to paralyze intruders in their hive is know as 2-heptanone. The formula for this compound is shown.

How many atoms of each element are in one molecule of 2-heptanone?

• 4 carbons, 11 hydrogens, 1 oxygen

• 7 carbons, 14 hydrogens, 1 oxygen

• 7 carbons, 11 hydrogens, 8 oxygens

• 6 carbons, 14 hydrogens, 3 oxygens

Tags

NGSS.MS-PS1-1

How many Al atoms are in this compound?         4Al₂O₃

• 2
• 8
• 6
• 4

Tags

NGSS.MS-PS1-1

What does the number 4 represent in 4NH₃?

• Subscript

• Superscript

• Coefficient

Tags

NGSS.MS-PS1-1

The coefficient in a chemical formula represents...

• the total number of atoms

• the number of atoms of that particular element

• the number of molecules

• it's the number outside of the parenthesis

According to the law of conservation of mass, how much zinc should have been produced?

• 256 grams

• 104 grams

• 128 grams

• 64 grams

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5