If 6.0 g of carbon combines with 16.0 g of oxygen to form 22.0 g of carbon dioxide, how much carbon and oxygen, in grams, is in 28.7 g carbon dioxide?
A) 20.9 g carbon and 7.8 g oxygen
B) 20.9 g carbon and 10.5 g oxygen
C) 7.8 g carbon and 20.9 g oxygen
D) 7.8 g carbon and 10.5 g oxygen
E) 3.9 g carbon and 20.9 g oxygen

Question

Quizplus · Accepted Answer

Using the given ratio of carbon to oxygen in carbon dioxide, we can calculate the amount of each element in 28.7 g of carbon dioxide.

1 mole of CO2 contains 1 mole of C and 2 moles of O. 
From the given data, we know that:

- The mass of C is 6.0 g
- The mass of O is 16.0 g 
- The total mass of CO2 is 22.0 g

Using these values, we can calculate the molar mass of CO2:

M(CO2) = 6.0 g + 2(16.0 g) = 38.0 g/mol

Now, we can use the molar mass of CO2 and the given mass of 28.7 g to calculate the amount of moles of CO2:

n(CO2) = 28.7 g / 38.0 g/mol = 0.756 mol

Since there is 1 mole of C for every mole of CO2, there must be 0.756 mol of C in 28.7 g of CO2. We can convert this to grams:

mass of C = n(C) x M(C) = 0.756 mol x 12.0 g/mol = 9.07 g

Similarly, there are 2 moles of O for every mole of CO2. The amount of moles of O in 28.7 g of CO2 is therefore:

n(O) = 2 x n(CO2) = 2 x 0.756 mol = 1.512 mol

Converting this to grams:

mass of O = n(O) x M(O) = 1.512 mol x 16.0 g/mol = 24.2 g

Therefore, there are 9.07 g of carbon and 24.2 g of oxygen in 28.7 g of carbon dioxide. 
So, the best choice is C: 7.8 g carbon and 20.9 g oxygen (rounding to one decimal place).

If 60 G of Carbon Combines with 16