Question

question select the correct answer. a scientist compares two samples of colorless gas present at the beginning and end of a lab process. she wants to determine whether a chemical reaction has occurred. she tests whether each gas is flammable. neither gas burns when lit. she then measures the amount of each gas. sample one has a volume of 53 cm³ and a mass of 0.10 g. sample two has a volume of 39 cm³ and a mass of 0.05 g. what are the scientists findings? the flammability test shows that the gases are the same, so a chemical reaction did not occur. the flammability test shows that the gases are different, so a chemical reaction occurred. density calculations show that the gases are the same, so a chemical reaction did not occur. density calculations show that the gases are different, so a chemical reaction occurred.

Explanation:

Step1: Calculate density of Sample 1

$
ho_1 = \frac{m_1}{V_1} = \frac{0.10\ \text{g}}{53\ \text{cm}^3} \approx 0.00189\ \text{g/cm}^3$

Step2: Calculate density of Sample 2

$
ho_2 = \frac{m_2}{V_2} = \frac{0.05\ \text{g}}{39\ \text{cm}^3} \approx 0.00128\ \text{g/cm}^3$

Step3: Compare densities

$
ho_1
eq
ho_2$, so gases are different; chemical reaction occurred.

Answer:

Density calculations show that the gases are different, so a chemical reaction occurred.