Question

a sample of an unknown pure substance x is analyzed and found to contain 4.67 g of element e₁, 5.33 g of element e₂, and no other elements. a similar analysis is made of three other substances that also only contain elements e₁ and e₂. the results are shown in the table below. decide whether each of the other substances is also a pure substance. if you dont have enough information to decide, choose cant decide

Explanation:

Step1: Calculate ratio for substance X

For substance X, the ratio of mass of $E_1$ to mass of $E_2$ is $\frac{4.67}{5.33}\approx0.88$.

Step2: Calculate ratios for other substances

For substance A, the ratio of mass of $E_1$ to mass of $E_2$ is $\frac{13.8}{5.24}\approx2.63$. Since this ratio is different from that of X, substance A is a mixture.
For substance B, the ratio of mass of $E_1$ to mass of $E_2$ is $\frac{18.1}{23.9}\approx0.76$. Since this ratio is different from that of X, substance B is a mixture.
For substance C, the ratio of mass of $E_1$ to mass of $E_2$ is $\frac{26.4}{7.55}\approx3.49$. Since this ratio is different from that of X, substance C is a mixture.

Answer:

substance	mass of $E_1$	mass of $E_2$	pure substance?
B	18.1 g	23.9 g	mixture
C	26.4 g	7.55 g	mixture