First you need to find the amount of mass of Na2CO3 in one moles
(Use periodic chart)
Na= 22.99 x 2 = 45.98
C = 12.01
O = 16.00 x 4 = 64.00
Add the molar masses together to get 121.99
To find how many grams are in 4 moles, times 121.99 by 4
This gives you 487.96
But the questions asks for the answer to be in kilograms nor grams, to change into kilograms divide by 1000
This gets you the answer: 0.49 kg
Answer:
Concentration for the solution is 0.153 mol/L
Explanation:
Formula for the osmotic pressure is π = M . R . T . i
where M is molarity (concentration), R the universal constant for gases and T is Absolute T° (T°C + 273)
π = Osmotic pressure.
Let's replace the data given:
3.9 atm = M . 0.082L.atm/mol.K . 310K
3.9 atm / 0.082 mol.K/L.atm . 310K = 0.153 mol/L (M)
i = Van't Hoff factor (ions from the solute dissolved in solution)
In this case, we assumed no ion pairing, so i = 1
Molarity is defined as number of moles of solute in 1 L of solution.
Here, 0.1025 g of Cu is reacted with 35 mL of HNO_{3} to produced Cu^{2+} ions.
The balanced reaction will be as follows:
Cu+3HNO_{3}\rightarrow Cu(NO_{3})_{2}+NO_{2}+H_{2}O
From the above reaction, 1 mole of Cu produces 1 mole of Cu^{2+}, convert the mass of Cu into number of moles as follows:
n=\frac{m}{M}
molar mass of Cu is 63.55 g/mol thus,
n=\frac{0.1025 g}{63.55 g/mol}=0.0016 mol
Now, total molarity of solution, after addition of water is 200 mL or 0.2 L can be calculated as follows:
M=\frac{n}{V}=\frac{0.0016 mol}{0.2 L}=0.008 mol/L=0.008 M
Thus, molarity of Cu^{2+} is 0.008 M.
We have to know the number of Na⁺ ions in the unit cell.
The number of Na⁺ ions in the unit cell is (D) 8.
Sodium oxide (Na2O) crystallizes in a structure in which the O2– ions are in a face - centered cubic lattice and the Na+ ions are in tetrahedral holes.
O²⁻ ions are in a face centred cubic lattice, so the number of O²⁻ ions per unit cell is equal to 4. The number of tetrahedral hole= 2 X 4=8. Na+ ions are present in tetrahedral holes, which indicates there are 8 number of Na+ ions in the unit cell.
Answer : The molar mass of protein is, 
Explanation :
Formula used :
where,
= osmotic pressure = 0.138 atm
C = concentration
R = solution constant = 0.0821 L.atm/mol.K
T = temperature = 
w = mass of protein subunit = 0.155 g
M = molar mass of protein subunit = ?
V = volume of solution = 2.00 mL
Now put all the given values in the above formula, we get:
Therefore, the molar mass of protein is,
