Chemistry Investigation Quiz

Some students in a chemistry lab conducted an investigation in which they added four different solid substances to separate beakers of water. They stirred the mixtures for one minute and then recorded their observations in the table below. Which substance most likely caused a new substance to be formed when mixed with water?

• Substance 1

• Substance 2

• Substance 3

• Substance 4

Which of these formulas contain equal numbers of nitrogen atoms?

• Formulas I and III

• Formulas I and IV

• Formulas I, II and V

• Formulas II and III

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₂SO₄

• HClO₃

• H₃PO₄

• H₂O

The equation below represents a chemical reaction that occurs in living cells. How many atoms are represented in the reactants of this equation?

• 6

• 36

• 12

• 24

A scientist spilled a few drops of dilute hydrochloric acid (HCl) on a lab table. The scientist sprinkled some baking soda (NaHCO3) onto the spill for safety purposes. Which observation would provide the best evidence that a chemical reaction occurred?

• The baking soda absorbed the hydrochloric acid

• The baking soda and hydrochloric acid combined, and gas bubbles formed

• Some of the baking soda dissolved in the hydrochloric acid

• The hydrochloric acid evaporated, leaving only the baking soda

Which information could a student determine from only the chemical formula of a protein?

• The number of molecules in each sequence that makes up a protein

• The physical arrangement of atoms in the structure of the protein

• The number of atoms of each element in the protein

• The color of the protein

During an investigation, a student combined the two clear, colorless solutions shown below. The student observed that the temperature changed from 25 degrees Celsius to 23 degrees Celsius when the solutions were combined and that a white substance rapidly formed and settled to the bottom of the container. What most likely happened to produce these results?

• One of the original compounds came out of solution

• Rapid evaporations of water occurred, leaving a solid

• Some of the water froze into ice crystals

• The solutions reacted chemically

Serotonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula for one molecule of serotonin is C₁₀H₁₂N₂O. How many total atoms are in Serotonin?

• 25

• 24

• 26

• 23

How many atoms of oxygen are in the molecule of glucose (C₆H₁₂O₆)?

• 4

• 5

• 6

• 7

Select the coefficient on the reactants side of the following equation.

• 2

• 1

• 3

• 4