Answer:
2. 14
Explanation:
To form Br₂ bond, a total of 14 electrons are needed.
Bromine is an element in the 7th group on the periodic table. It has 7 valence electrons.
- In forming the bromine gas, the two atoms of bromine shares 7 electrons each.
- These electrons are from their outermost shell.
- The outermost shell is the valence shell.
- So, two atoms donating 7 electrons gives 14 electrons.
Buffers - mixtures of conjugate acid and conjugate base at ±1 pH unit from pH = pKa. Resistant to changes in pH in response to small additions of H+ or OH-. ... Polyprotic acids - dissociation of each H+ can be treated separately if the pKa values are different
Answer:
31.24 kJ
Explanation:
- SiO₂(g) + 3C(s) → SiC(s) + 2CO(g) ΔH° = 624.7 kJ/mol
First we <u>convert 3.00 grams of SiO₂ to moles</u>, using its <em>molar mass</em>:
- 3.00 g SiO₂ ÷ 60.08 g/mol = 0.05 mol
Now we <u>calculate the heat absorbed</u>, using the <em>given ΔH°</em>:
If the complete reaction of 1 mol of SiO₂ absorbs 624.7 kJ, then with 0.05 mol:
- 0.05 mol * 624.7 kJ/mol = 31.24 kJ of heat would be absorbed.
Answer:
The potential energy decreases whereas the kinetic energy increases.
