Answer:
294.87 gm CaCl_2
Explanation:
The computation of the mass of calcium chloride is shown below:
But before that following calculations need to be done
Number of moles of chlorine atom is
= 3.20 × 10^24 ÷ 6.022 × 10^23
= 5.314 moles
As we know that
1 mole CaCl_2 have the 2 moles of chlorine atoms
Now 5.341 mole chloride atoms would be
= 1 ÷ 2 × 5.314
= 2.657 moles
Now
Mass of CaCl_2 = Number of moles × molar mass of CaCl_2
= 2.657 moles × 110.98 g/mol
= 294.87 gm CaCl_2
When we can get Pka for K2HPO4 =6.86 so we can determine the Ka :
when Pka = - ㏒ Ka
6.86 = -㏒ Ka
∴Ka = 1.38 x 10^-7
by using ICE table:
H2PO4- → H+ + HPO4
initial 0.4 m 0 0
change -X +X +X
Equ (0.4-X) X X
when Ka = [H+][HPO4] / [H2PO4-]
by substitution:
1.38 X 10^-7 = X^2 / (0.4-X) by solving for X
∴X = 2.3x 10^-4
∴[H+] = X = 2.3 x 10^-4
∴PH = -㏒[H+]
= -㏒ (2.3 x 10^-4)
∴PH = 3.6
Answer:
D. Mass is the amount of matter and weight is the effect of gravity on mass.
Explanation:
Mass is, by definition, the amount of matter that makes up an object. The weight of an object is directly related to the pull of gravity.
A. the number of protons in the atoms
