Answer:
The percent composition is 21% N, 6% H, 24% S and 49% O.
Explanation:
1st) The molar mass of (NH4)2SO4 is 132g/mol, and it represents the 100% of the mass composition.
In 1 mole of (NH4)2SO4, there are:
- 2 moles of N.
- 8 moles of H.
- 1 mole of S.
- 4 moles of O.
2nd) It is necessary to calculate the mass of each element, multiplying its molar mass by the number of moles:
- 2 moles of N (14g/mol) = 28g
- 8 moles of H (1g/mol) = 8g
- 1 mole of S (32g/mol) = 32g
- 4 moles of O (16g/mol) = 64g
3rd) With a mathematical rule of three we can calculate the percent composition of each element in the molecule of (NH4)2SO4:




In this case, we can calculate the percent composition of Oxygen by subtracting the other percentages, since the total must be 100%.
So, the percent composition is 21% N, 6% H, 24% S and 49% O.
Answer:
0.127M
Explanation:
Molarity of a solution = number of moles (n) ÷ volume (V)
Molar mass of Mg(NO3)2 = 24 + (14 + 16(3)}2
= 24 + {14 + 48}2
= 24 + 124
= 148g/mol
Using the formula, mole = mass/molar mass, to convert mass of Mg(NO3)2 to mole
mole = 14g ÷ 148g/mol
mole = 0.095mol
Volume = 750mL = 750/1000 = 0.75L
Molarity = 0.095mol ÷ 0.75L
Molarity = 0.127M
Answer:6.94
Explanation:
Molar mass of CaCO3=40+12+16×3
=40+12+48=100g/mol
Moles=mass of substance/molar mass
=97mg/100g=0.097/100=0.00097moles/L.
PH=-log[CaCo3]=-log(0.00097)=6.94
P.s it's log to base e