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 one

The density formula is $
ho=\frac{m}{V}$. For sample one, $m = 0.10\ g$ and $V=53\ cm^{3}$, so $
ho_1=\frac{0.10}{53}\ g/cm^{3}\approx 0.00189\ g/cm^{3}$.

Step2: Calculate density of sample two

For sample two, $m = 0.05\ g$ and $V = 39\ cm^{3}$, so $
ho_2=\frac{0.05}{39}\ g/cm^{3}\approx0.00128\ g/cm^{3}$.

Step3: Analyze results

Since $
ho_1
eq
ho_2$, the gases are different. A chemical - reaction likely occurred. Also, the flammability test only shows non - flammability, not whether the gases are the same or different.

Answer:

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