Question

35.35 2120 What is the molecular formula of a compound that contains 10.0 g carbon, 1.68 g hydrogen, and 13.4 g oxygen? The molar mass of this compound is 60.0 g/mol. Select the correct answer below: O CHO OCHO O C,H,O, O C,H,O, FEEDBACK Content attribution QUESTION 12 - 1 POINT Adiluted solution as the same amount of solute but solvent than the concentrated solution Select the correct answer below! more o less O as much O a different FEEDBACK

Answer 1

1). To find the molecular formula, the following steps are to be followed:

Step 1: Change the given masses to moles

Given:

Carbon = 10.0 g

Hydrogen = 1.68 g

Oxygen = 13.4 g

$For Carbon:\frac{10.0g}{12.0 g mol^{-1}} = 0.833 moles$

$For Hydrogen:\frac{1.68 g}{1.0 g mol^{-1}} = 1.68 moles$

$For Oxygen:\frac{13.4 g}{16.0 g mol^{-1}} = 0.83 moles$

Step II: Find a ratio between the moles to determine the empirical formula

The ratio of Carbon and Oxygen is 1:1 as

$\frac{0.833}{0.833} = 1$

Next, the ratio of Hydrogen to both Cabon and Oxygen is 2:1

$\frac{1.68}{0.833} = 2$

So the ratio is 1 C to 1 O to 2 H

Therefore the empirical formula comes out to be CH₂O.

Step III: Finding the Molecular Formula

From the empirical formula calculated above, i.e., CH₂O the molar mass comes out to be 30.0 g mol^-1 as

12 g (C) + 2*1 g (H) 16g (O) = 30.0 g mol^-1

But the given molar mass of the compound is 60 g mol^-1. Therefore, we need to multiply the emperical formula by 2 to get this molar mass of 60 g mol^-1.

Therefore, the molecular forula of the compund is C₂H₄O₂. Hence, Option (C) is the correct option.

2). A solution is diluted by adding more amount of solvent in it while keeping the amount of solute constatnt. Therefore option (A) more is the correct option