Heat required to vaporize 1 mol of water from water at 100C to steam at 100C = 40.7 kJ
<span>1 mol of water weighs = 18.015g
</span>1.55 kg = <span>1550/18.015 mol = 86.03 mol
</span><span>Heat required to vaporize :
</span>= 86.03 mol x <span>40.7 kJ
</span>
= 3501.421 kJ
Answer : The mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2 and
the mole ratios of Hydrazine to water is 1 : 4.
Explanation :
The balanced chemical equation is,

According to the given reaction,
1 mole of Hydrazine react with the 2 moles of Hydrogen peroxide.
Therefore, the mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2
And in case of Hydrazine and water,
1 mole of Hydrazine gives 4 moles of water.
Therefore, the mole ratios of Hydrazine to water is 1 : 4
Answer:
1.7 mL
Explanation:
<em>A chemist must prepare 550.0 mL of hydrochloric acid solution with a pH of 1.60 at 25 °C. He will do this in three steps: Fill a 550.0 mL volumetric flask about halfway with distilled water. Measure out a small volume of concentrated (8.0 M) stock hydrochloric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrochloric acid that the chemist must measure out in the second step. Round your answer to 2 significant digits.</em>
Step 1: Calculate [H⁺] in the dilute solution
We will use the following expresion.
pH = -log [H⁺]
[H⁺] = antilog - pH = antilog -1.60 = 0.0251 M
Since HCl is a strong monoprotic acid, the concentration of HCl in the dilute solution is 0.0251 M.
Step 2: Calculate the volume of the concentrated HCl solution
We want to prepare 550.0 mL of a 0.0251 M HCl solution. We can calculate the volume of the 8.0 M solution using the dilution rule.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂/C₁
V₁ = 0.0251 M × 550.0 mL/8.0 M = 1.7 mL
Do you know what is meant by needed? does it mean lone pairs?
Hepta is seven and tetra is four, so option c is your answer