Question

Can someone plz help me on this. I need it really bad

Answer 1

Answer:

-  40.66

-  9.91

Explanation:

For the first question:

Our theoretical compound is MR₂

1 mol of MR₂ contains 1 mol of M and 2 moles of R

Let's find out the molar mass:

9.45 g/mol + 18.12 g/mol . 2 = 45.69 g/mol

We can solve this, by an easy rule of three:

1 mol of MR₂ weighs 45.69 grams

Then, 0.89 moles may weigh 40.66 g

For the second question:

Our theoretical compound is D₂G

Let's determine the molar mass:

11.45 g/mol . 2 + 44.57 g/mol = 67.47 g/mol

1 mol of anything contains 6.02×10²³ molecules. By this definition we can say that 6.02×10²³ molecules weigh 67.47 grams. Let's solve by the rule of three:

6.02×10²³ molecules weigh 67.47 g

8.84×10²² molecules may weigh (8.84×10²² . 67.47 ) / 6.02×10²³ = 9.91 g