Question

A metal, M, forms an oxide having the formula MO2 containing 59.93% metal by mass. Determine the atomic weight in g/mole of the metal (M). Please provide your answer in 2 decimal places.

a. How many moles of oxygen atoms are found in 4.00 g of O2?
b. How many atoms of hydrogen are found in 0.400 mol of H2S?
c. How many hydrogen atomsare present in 0.235 g of NH3?

Answer 1

See solution.

Step-by-step explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to set up the formula for the calculation of the by-mass percentage of the metal:

`\% M=(m_M)/(m_M+2*m_O)*100 \%\\\\59.93\% =(m_M)/(m_M+32.00)*100 \%`

Thus, we solve for the molar mass of the metal to obtain:

`59.93\% (m_M+32.00) =m_M*100 \%\\\\m_M*59.93\% +1917.76\% =m_M*100 \%\\\\m_M=47.86g/mol`

For the subsequent problems, we proceed as follows:

a.

`4.00gO_2*(1molO_2)/(32.00gO_2)=0.125molO_2`

b.

`0.400molH_2S*(2molH)/(1molH_2S)*(6.022x10^(23)atomsH)/(1molH)=4.82x10^(23)atomsH`

c.

`0.235gNH_3*(1molNH_3)/(17.03gNH_3) *(3molH)/(1molNH_3)*(6.022x10^(23)atomsH)/(1molH)=2.49x10^(22)atomsH`

Regards!