80.5%- The total mass of the compound is 18g (14.5 + 3.5) then divide the mass of magnesium by the total. easy way to remember is- (part/whole) x 100
Answer:
80.13g of SO2
Explanation:
4FeS2 + 11O2 —> 2Fe2O3 + 8SO2
Molar Mass of FeS2 = 55.8 + (2x32) = 119.8g/mol
Mass of FeS2 from the balanced equation = 4 x 119.8 = 479.2
Molar Mass of SO2 = 32 + (16x2) = 32 + 32 = 64g/mol
Mass of SO2 from the balanced equation = 8 x 64 = 512g
From the equation,
479.2g of FeS2 produced 512g of SO2.
Therefore, 75g of FeS2 will produce = (75 x 512)/479.2 = 80.13g of SO2
answer: D
Here is a list of the most common ways to speed up a chemical reaction
Increase the temperature (reactions that absorb energy)
Decrease the temperature (Reactions that release energy)
<u>Answer:</u> The molar mass of molecule X is 162.5 g/mol
<u>Explanation:</u>
We are given:
0.9 % of NaCl
This means that 0.9 grams of NaCl is present in 100 grams of solution
5 % of molecule X
This means that 5 grams of molecule X is present in 100 grams of solution
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
![\pi=iMRT](https://tex.z-dn.net/?f=%5Cpi%3DiMRT)
Or,
![\pi=i\times \frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}\times RT](https://tex.z-dn.net/?f=%5Cpi%3Di%5Ctimes%20%5Cfrac%7B%5Ctext%7BMass%20of%20solute%7D%7D%7B%5Ctext%7BMolar%20mass%20of%20solute%7D%5Ctimes%20%5Ctext%7BVolume%20of%20solution%20%28in%20L%29%7D%7D%5Ctimes%20RT)
where,
i = Van't hoff factor
R = Gas constant = ![0.0821\text{ L atm }mol^{-1}K^{-1}](https://tex.z-dn.net/?f=0.0821%5Ctext%7B%20L%20atm%20%7Dmol%5E%7B-1%7DK%5E%7B-1%7D)
T = temperature of the solution
According to the question:
Osmotic pressure of both the solutions are same.
So, the equation becomes:
![i_{NaCl}\times \frac{m_{NaCl}}{M_{NaCl}\times V}\times RT=i_X\times \frac{m_X}{M_X\times V}\times RT](https://tex.z-dn.net/?f=i_%7BNaCl%7D%5Ctimes%20%5Cfrac%7Bm_%7BNaCl%7D%7D%7BM_%7BNaCl%7D%5Ctimes%20V%7D%5Ctimes%20RT%3Di_X%5Ctimes%20%5Cfrac%7Bm_X%7D%7BM_X%5Ctimes%20V%7D%5Ctimes%20RT)
where,
![i_{NaCl}=2\\m_{NaCl}=0.9g\\M_{NaCl}=58.5g/mol\\i_X=1\text{ (for non-electrolytes)}\\m_X=5g\\M_X=?g/mol](https://tex.z-dn.net/?f=i_%7BNaCl%7D%3D2%5C%5Cm_%7BNaCl%7D%3D0.9g%5C%5CM_%7BNaCl%7D%3D58.5g%2Fmol%5C%5Ci_X%3D1%5Ctext%7B%20%28for%20non-electrolytes%29%7D%5C%5Cm_X%3D5g%5C%5CM_X%3D%3Fg%2Fmol)
Putting values in above equation, we get:
![2\times \frac{0.9}{58.5\times V}\times RT=1\times \frac{5}{M_X\times V}\times RT\\\\M_X=\frac{1\times 5\times 58.5}{0.9\times 2}=162.5g/mol](https://tex.z-dn.net/?f=2%5Ctimes%20%5Cfrac%7B0.9%7D%7B58.5%5Ctimes%20V%7D%5Ctimes%20RT%3D1%5Ctimes%20%5Cfrac%7B5%7D%7BM_X%5Ctimes%20V%7D%5Ctimes%20RT%5C%5C%5C%5CM_X%3D%5Cfrac%7B1%5Ctimes%205%5Ctimes%2058.5%7D%7B0.9%5Ctimes%202%7D%3D162.5g%2Fmol)
Hence, the molar mass of molecule X is 162.5 g/mol
Answer:
8.00 moles.
Explanation:
The ratio of Fe to FeO is 2:2 = 1:1, so 8 moles are produced.