. Three students are asked to discuss why the CO2 produced from the reaction

rose upward out of the mouth of the test tube even though CO2 is denser than

air. Select the student that employs correct scientific reasoning.

Student 1: The reason the carbon dioxide rose despite being denser than air is because the heat

caused it to condense.

• Student 2: The carbon dioxide produced by decomposition of baking soda was able to rise above

the air because the oxygen in the test tube was consumed.

• Student 3: The carbon dioxide rose up because the heat expanded the gas and it became less

dense.

O Student 3

OStudent 1

O Student 2

Student 3

Explanation:

This question lets us know something about how the density of a gas varies with temperature.

When a gas is heated, its molecules spread out and expand. When this happens, the volume of the gas increases. Remember that density is defined as mass/volume. Thus as the volume increases, the density of the gas decreases.

Therefore, the carbon dioxide rose up because the heat expanded the gas and it became less dense.

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b