For atoms use a periodic table. The atomic number is the amount of atoms. For molecules and ions look up things revolved around the avogrados principle
Answer:
The white powder is sodium carbonate
Explanation:
If you supposed an ammount of 100 grams of the white powder, it means there are 42.59 grams of Na, 12.02 grams of C and 44.99 grams of O. If you divided every compound by its molar mass, you will know the moles of every compound. (According to moles=mass (grams)/ molar mass (grams/mole)
C=12.01 g/mole, Na=23 g/mole, O=16 g/mole
So:
C=12.02/12.01= 1.0 moles, Na=42.59/ 23= 1.85 moles, O= 44.99/16= 2.81 moles
Knowing this, we can stimated that the white powder has 1 mol of C and approximately 2 and 3 moles of N and O, respectively
Chemical formula for sodium carbonate is Na2CO3 and the formula for sodium oxalate is Na2C2O4. So the white powder is Na2CO3
Answer:
![C_2H_6](https://tex.z-dn.net/?f=C_2H_6)
Explanation:
Hello.
In this case, we can see that the mass of carbon of the unknown compound comes from the yielded mass of carbon dioxide, thus, we compute the moles of carbon as follows:
![m_C=10.2gCO_2*\frac{1molCO_2}{44gCO_2}*\frac{1mol C}{1molCO_2}=0.232 molC](https://tex.z-dn.net/?f=m_C%3D10.2gCO_2%2A%5Cfrac%7B1molCO_2%7D%7B44gCO_2%7D%2A%5Cfrac%7B1mol%20C%7D%7B1molCO_2%7D%3D0.232%20molC)
Moreover, the mass of hydrogen comes from the yielded water, therefore we can also compute the moles of water:
![m_H=6.3gH_2O*\frac{1molH_2O}{18gH_2O}*\frac{2molH_2}{1molH_2O} =0.7molH](https://tex.z-dn.net/?f=m_H%3D6.3gH_2O%2A%5Cfrac%7B1molH_2O%7D%7B18gH_2O%7D%2A%5Cfrac%7B2molH_2%7D%7B1molH_2O%7D%20%20%3D0.7molH)
Then, to find the subscripts in the empirical formula, we divide by the moles of carbon as the smallest:
![C:\frac{0.232}{0.232}=1\\ \\H:\frac{0.7}{0.232}=3](https://tex.z-dn.net/?f=C%3A%5Cfrac%7B0.232%7D%7B0.232%7D%3D1%5C%5C%20%5C%5CH%3A%5Cfrac%7B0.7%7D%7B0.232%7D%3D3)
Whose molar mass is:
![M_{CH_3}=12+1*3=15g/mol](https://tex.z-dn.net/?f=M_%7BCH_3%7D%3D12%2B1%2A3%3D15g%2Fmol)
Thus, the ratio of the molecular formula to the empirical formula is:
![\frac{30}{15}=2](https://tex.z-dn.net/?f=%5Cfrac%7B30%7D%7B15%7D%3D2)
Therefore, the molecular formula is twice the empirical formula:
![C_2H_6](https://tex.z-dn.net/?f=C_2H_6)
Which is actually ethane.
Regards.
First, calculate the amount fo Na2O that should be produced with the given amount of sodium using proper dimensional analysis and the balanced chemical reaction,
theoretical amount of Na2O = (54.1 g of Na)(1 mol Na/23 g Na)(2 mos Na2O/4 mols Na)(62 g Na2O/ 1mol Na2O)
theoretical amount of Na2O = 72.9 g of Na2O
Calculation of percent yield,
% yield = (61.8 g Na2O) / (72.9 g of Na2O) x 100%
% yield = 84.75%
Answer: 84.75%