Answer:
The ΔH is 5.5 kJ/mol and the reaction is endothermic.
Explanation:
To calculate the ∆H (heat of reaction) of the combustion reaction, that is, the heat that accompanies the entire reaction, you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient ( number of molecules of each compound participating in the reaction) and finally subtract them:
Combustion enthalpy = ΔH = ∑H products - ∑Hreactants
In this case:
ΔH = 15.7 kJ/mol - 10.2 kJ/mol= 5.5 kJ/mol
An endothermic reaction is one whose enthalpy value is positive, that is, the system absorbs heat from the environment (ΔH> 0).
<u><em>The ΔH is 5.5 kJ/mol and the reaction is endothermic.</em></u>
Answer:
d) V = 91.3 L
Explanation:
Given data:
Volume of nitrogen = ?
Temperature = standard = 273.15 K
Pressure = standard = 1 atm
Number of atoms of nitrogen = 2.454×10²⁴ atoms
Solution:
First of all we will calculate the number of moles of nitrogen by using Avogadro number.
1 mole = 6.022×10²³ atoms
2.454×10²⁴ atoms × 1 mol / 6.022×10²³ atoms
0.407×10¹ mol
4.07 mol
Volume of nitrogen:
PV = nRT
1 atm × V = 4.07 mol ×0.0821 atm.L /mol.K ×273.15 K
V = 91.3 atm.L /1 atm
V = 91.3 L
<h2>Question↷</h2>
Which of these solutions is the most basic?
[OH-] = 4.3 x 10-9 M
[OH-] = 2.8 x 10-11 M
[OH-] = 6.7 x 10-10 M
[OH-] = 1.0 x 10-5 M
<h2>Answer↷</h2>
- <u>[OH-] = 1.0 x 10-5 M</u> ✓
<h2>Solution↷</h2>
[OH-] = 4.3 x 10-9 M
- [OH-] = 4.3 x 10^-9 M
- pOH = - log [OH^1-]
- pOH = - log [4.3 x 10^-9]
- pOH = 8.36
- pH = 14- 8.36
- pH = 5.64
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[OH-] = 2.8 x 10-11 M
- [OH-] = 2.8 x 10^-11 M
- pOH = - log [OH^1-]
- pOH = - log [2.8 x 10^-11 ]
- pOH = 10.55
- pH = 14-10.55
- pH = 3.45
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[OH-] = 6.7 x 10-10 M
- [OH-] = 6.7 x 10^-10 M
- pOH = - log [OH^1-]
- pOH = - log [6.7 x 10^-10]
- pOH = 9.17
- pH = 14-9.17
- pH = 4.83
_______________________________________
[OH-] = 1.0 x 10-5 M
- [OH-] = 1.0 x 10-5 M
- pOH = - log [OH^1-]
- pOH = - log [1.0 x 10^-5 ]
- pOH = 5
- pH = 14-5
- pH = 9
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we know that , the solution with <u>pH > 7</u> is termed as basic and more the pH ,more the basicity, hence ,the solution with the highest pH would be the strongest base out of these all which is
<u>[OH-] = 1.0 x 10-5 M</u> with pH = 9
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