Answer:
0.086
Explanation:
A 5.2 molal aqueous solution of methyl alcohol indicates that 5.2 moles of methyl alcohol are present in 1 kilogram (or 1000 g) of water. Water has a molecular weight of 18 g/mol.
(100g)/18g/mol=55.56 mol
5.2 mol/(5.2mol+55.56 mol)=0.086
Answer:
399
Explanation:
Pb(SO4)2 contains 1 atom of Pb, 2 atoms of S and 8 atoms of O. So, atomic mass of Pb(SO4)2 is 207 + 64 + 128 = 399 u. Therefore, molar mass of Pb(SO4)2 is 399 g/mol.HOPE THIS helps. Good Luck
It is the smallest unit it is what makes up everything
joke-Don't trust Atoms they make up everything
D is the correct answer
every other option contains an element
Answer:
6.4 × 10^-10 M
Explanation:
The molar solubility of the ions in a compound can be calculated from the Ksp (solubility constant).
CaF2 will dissociate as follows:
CaF2 ⇌Ca2+ + 2F-
1 mole of Calcium ion (x)
2 moles of fluorine ion (2x)
NaF will also dissociate as follows:
NaF ⇌ Na+ + F-
Where Na+ = 0.25M
F- = 0.25M
The total concentration of fluoride ion in the solution is (2x + 0.25M), however, due to common ion effect i.e. 2x<0.25, 2x can be neglected. This means that concentration of fluoride ion will be 0.25M
Ksp = {Ca2+}{F-}^2
Ksp = {x}{0.25}^2
4.0 × 10^-11 = 0.25^2 × x
4.0 × 10^-11 = 0.0625x
x = 4.0 × 10^-11 ÷ 6.25 × 10^-2
x = 4/6.25 × 10^ (-11+2)
x = 0.64 × 10^-9
x = 6.4 × 10^-10
Therefore, the molar solubility of CaF2 in NaF solution is 6.4 × 10^-10M
