First, we need to get the concentration of [NaH2PO4]:
[NaH2PO4] =( mass / molar mass ) * volume L
when we have mass NaH2PO4 = 6.6 g & molar mass = 120g/mol & V = 0.355 L
So by substitution:
[NaH2PO4] = (6.6g / 120g/mol) * 0.355 L = 0.0195 M
then, we need to get the concentration of [Na2HPO4]:
[Na2HPO4]= (mass / molar mass ) * volume L
So by substitution:
[Na2HPO4] = (8g/ 142g/mol) * 0.355 L = 0.02 M
and when Pka of the 2nd ionization of phosphoric acid = 7.21
So by substitution in the following formula, we can get the PH:
PH = Pka + ㏒[A]/[AH]
∴PH = 7.21 + ㏒[0.02]/[0.0195]
∴ PH = 7.2
Answer:
1.17 grams of HCl can neutralize 2.7 grams sodium bicarbonate
Explanation:
Step 1: Data given
Mass of sodium bicarbonate = 2.7 grams
Step 2: The balanced equation
HCl + NaHCO3 ⇔ NaCl + H2O + CO2
Step 3: Calculate moles NaHCO3
moles NaHCO3 =2.7 g / 84 g/mol= 0.032 moles
Step 4: Calculate moles HCl
For 1 mol NaHCO3 we need 1 mol HCl
For 0.032 moles NaHCO3 = 0.032 moles HCl
Step 5: Calculate mass HCl
Mass HCl = moles HCl * molar mass HCl
mass HCl = 0.032 * 36.46 g/mol= 1.17 grams
1.17 grams of HCl can neutralize 2.7 grams sodium bicarbonate
Answer:
1a. Both sides of the decay reaction have the same charge.
b. The number of nucleons on both sides are the same.
2. The binding energy of one mole of the atom is 17.172 ×
J.
Explanation:
1a. Considering the two sides of the decay reaction and with respect to the law of conservation of charge, it can be observed that both sides have the same charge. Charge can not be created or destroyed in the process.
b. The number of nucleons on both sides are equal. No nucleon is created or destroyed in the process.
2. Binding energy is the minimum energy required to separate an atom into its nucleons. From Einstein's energy equation;
E = Δm
Where E is the binding energy of the atom, Δm is the mass defect and c is the speed of light.
Given that: Δm = 1.908 g/mol and c = 3 ×
. So that:
E = 1.908 × 
= 1.908 × 9 × 
= 17.172 ×
J
The binding energy of one mole of the atom is 17.172 ×
J.