Question

question 6
1 pts
a nitrogen oxide is 63.65% by mass nitrogen. the molecular formula could be
________.
o either no2 or n2o4
o n2o
o no
o n2o4
o no2
question 7
1 pts
there are________mol of carbon atoms in 4 mol of c4h8o2.
o 8
o 32
o 20
o 4
o 16

Explanation:

Question 6

Step1: Calculate mass percentage of N for each compound

• For \(N_2O\):

Molar mass of \(N_2O=(2\times14)+16 = 44\space g/mol\). Mass percentage of \(N=\frac{2\times14}{44}\times100\%\approx63.64\%\)

• For \(NO\):

Molar mass of \(NO = 14 + 16=30\space g/mol\). Mass percentage of \(N=\frac{14}{30}\times 100\%\approx46.67\%\)

• For \(NO_2\):

Molar mass of \(NO_2=14+(2\times16)=46\space g/mol\). Mass percentage of \(N=\frac{14}{46}\times100\%\approx30.43\%\)

• For \(N_2O_4\):

Molar mass of \(N_2O_4=(2\times14)+(4\times16)=92\space g/mol\). Mass percentage of \(N=\frac{2\times14}{92}\times100\%\approx30.43\%\)

Step1: Analyze the formula \(C_4H_8O_2\)

In one molecule of \(C_4H_8O_2\), there are 4 carbon atoms.

Step2: Calculate moles of C atoms

If we have 4 mol of \(C_4H_8O_2\), then moles of C atoms \(=4\times4 = 16\space mol\)

Answer:

\(N_2O\)

Question 7