Answer:
B) 16 g
Explanation:
First we <u>convert 4 moles of O₂ into moles of H₂</u>, using the <em>stoichiometric coefficients of the balanced reaction</em>:
- 4 mol O₂ *
= 8 mol H₂
Finally we <u>convert 8 moles of H₂ into grams</u>, using <em>its molar mass</em>:
- 8 mol H₂ * 2 g/mol = 16 g
Thus, the correct answer is option B).
Answer:
Mass of solute = 0.0036 g
Explanation:
Given data:
Concentration of Cl⁻ = 15.0 ppm
Volume of water = 240 mL
Mass of Cl⁻ present = ?
Solution:
1 mL = 1 g
240 mL = 240 g
Formula:
ppm = mass of solute / mass of sample ×1,000,000
by putting values,
15.0 ppm = (mass of solute / 240 g) ×1,000,000
Mass of solute = 15.0 ppm × 240 g / 1,000,000
Mass of solute = 0.0036 g
I think it is D I'm not positive
Answer:
kJ/mol
Explanation: <u>Enthalpy</u> <u>Change</u> is the amount of energy in a reaction - absorption or release - at a constant pressure. So, <u>Standard</u> <u>Enthalpy</u> <u>of</u> <u>Formation</u> is how much energy is necessary to form a substance.
The standard enthalpy of formation of HCl is calculated as:

→ 
Standard Enthalpy of formation for the other compounds are:
Calcium Hydroxide:
-1002.82 kJ/mol
Calcium chloride:
-795.8 kJ/mol
Water:
-285.83 kJ/mol
Enthalpy is given per mol, which means we have to multiply by the mols in the balanced equation.
Calculating:
![-17.2=[-795.8+2(285.85)]-[-1002.82+2\Delta H]](https://tex.z-dn.net/?f=-17.2%3D%5B-795.8%2B2%28285.85%29%5D-%5B-1002.82%2B2%5CDelta%20H%5D)



So, the standard enthalpy of formation of HCl is -173.72 kJ/mol