Answer: Fe(OH)2
Explanation: Fe has a charge of 2+ and OH has a charge of 1-. Switch the charges of the two elements to get the formula of Fe(OH)2.
Answer: 2.5 ml of 0.5 M HNO3 is necessary to titrate 25.0 mL of 0.05 M KOH
solution to the endpoint
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH.
We are given:
Putting values in above equation, we get:
Thus 2.5 ml of 0.5 M HNO3 is necessary to titrate 25.0 mL of 0.05 M KOH
solution to the endpoint
Answer:
65°C
Explanation:
Formula for calorimetry is:
Q = C . m . ΔT
Where Q is heat, C is specific heat, m is mass and ΔT is the difference between final T° and initial.
We have all data to replace.
First of all, we convert kJ to J → 4.94 kJ . 1000 J / 1 kJ = 4940 Joules
We made this conversion because the unit of C, is in J
As heat is lost, we have to think in a negative value. Let's replace:
- 4940 J = 4.18 J/ g °C . 35 g . ( Final T° - 98.8°C)
- 4940 J / (4.18 J/ g °C . 35 g) = Final T° - 98.8°C
Final T° = - 4940 J / (4.18 J/ g °C . 35 g) + 98.8°C
Final T° = 65.03 °C
Notice, that this answer has sense because as T° decreased, heat has been lost.
