Answer:
The correct reaction is as follows:
2Mg + O2 → 2MgO
3. Synthesis
Explanation:
Chemical reactions are of different types depending on how they occur. One of these types is called SYNTHESIS OR COMBINATION REACTION. A synthesis reaction is that reaction in which two atoms of two elements are chemically combined to form a single molecule or compound. That is;
A + B → AB.
This is the case in this question where atoms of Magnesium (Mg) and oxygen (O) reacted to form a single compound of Magnesium oxide (MgO). Hence, it is said to be a SYNTHESIS REACTION.
T₁=17+273=290 K
7.75x10⁴.850/290 = 8.10x10⁴.720/T₂
T₂=256.74 K = -16.26°C
Answer:
a) C6H5COOH + H2O ↔ H3O+ + C6H5COO-
b) [ H3O+ ] = 2.517 E-3 M
c) pH = 2.599
Explanation:
a) balanced equation:
C6H5COOH + H2O ↔ H3O+ + C6H5COO-
⇒ Ka = ( [ H3O+ ] * [ C6H5COO- ] ) / [ C6H5COOH ] = 6.5 E-5
mass balance:
0.10 m = [ C6H5COO- ] + [ C6H5COOH ].....(1)
charge balance:
[ H3O+ ] = [ C6H5COO- ] + [ OH- ] .......[ OH- ] : comes from water, it's not significant
⇒ [ H3O+ ] = [ C6H5COO- ] .........(2)
b) (2) in (1):
⇒ 0.10 M = [ H3O+ ] + [ C6H5COOH ]
⇒ [ C6H5COOH ] = 0.10 - [ H3O+ ]
⇒ Ka = [ H3O+ ]² / ( 0.1 - [ H3O+ ] ) = 6.5 E-5
⇒ [ H3O+ ]² + 6.5 E-5 [ H3O+ ] - 6.5 E-6 = 0
⇒ [ H3O+ ] = 2.517 E-3 M
c) pH = - log [ H3O+ ]
⇒ pH = - Log ( 2.517 E-3 )
⇒ pH = 2.599