The molar mass of the Carbon-12 from the periodic table is given to be 12.011 g. Multiply this mass with the number of moles given.
(0.25 moles) x (12.011 g / mole) = 3 g
Thus, the mass of 0.25 moles of carbon-12 is 3 g.
Answer:
0.4
Explanation:
Given parameters:
Mass of NaCl = 0.564g
Mass of KCl = 1.52g
Mass of LiCl = 0.857g
Unknown:
Mole fraction of KCl = ?
Solution:
First, find the number of moles of the given species;
Number of moles =
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Molar mass of LiCl = 7 + 35.5 = 42.5g/mol
Number of moles of KCl = = 0.02mol
Number of moles of NaCl = = 0.0096mol
Number of moles of LiCl = = 0.02mol
Sum of moles = 0.02mol + 0.0096mol + 0.02mol = 0.0496mol
Mole fraction of KCl = = 0.4
Answer:
0.15M
Explanation:
NaOH + HCl -->NaCl + H2O
moles of NaOH reacted with HCl
(0.5 × 30)/1000 = 1.5 × 10^ -3
so the moles of HCl reacted with NaOH
1.5 × 10^ -3
concentration of HCl = ( 1.5 × 10^ -3)/10 ×1000
True just because your parent is great at football does not mean that you will be as good as they were. They can teach you but you won't naturally be Olympic good if your parents are olympians