Answer:
Magnesium oxide is a binary compound of magnesium and oxygen while magnesium ribbon consists only of magnesium atoms.
Explanation:
The burning of magnesium in oxygen is a chemical change. It produces magnesium oxide having greater mass than magnesium ribbon. The greater mass results from the fact that the chemical reaction has added another element to the sample- oxygen. The mass of magnesium ribbon is the mass of magnesium atoms alone but in magnesium oxide, we consider the masses of magnesium and oxygen atoms making magnesium oxide heavier than magnesium ribbon.
We are going to use this formula:
Q = M*C*ΔT
when Q is the heat required
M is the mass of CCl4 = 10.35 g
C is the specific heat capacity of CCl4 = 0.874J/g.c
and ΔT the change in temperature = 56.4 - 32.1 °C =24.3 °C
∴ Q = 10.35g * 0.874 * 24.3 °C
= 219.8 J
Let's investigate the substances involved in the reaction first. The compound <span>CH3NH3+Cl- is a salt from the weak base CH3NH2 and the strong acid HCl. When this salt is hydrated with water, it will dissociate into CH3NH2Cl and H3O+:
CH3NH3+Cl- + H2O </span>⇒ CH3NH2Cl + H3O+
Nest, let's apply the ICE(Initial-Change-Equilibrium) table where x is denoted as the number of moles used up in the reaction:
CH3NH3+Cl- + H2O ⇒ CH3NH2Cl + H3O+
Initial 0.51 0 0
Change -x +x +x
-------------------------------------------------------------------------------
Equilibrium 0.51 - x x x
Then, let's find the equilibrium constant of the reaction. Since the reaction is hydrolysis we use KH, which is the ratio of Kw to Ka or Kb. Kw is the equilibrium constant for water hydrolysis which is equal to 1×10⁻¹⁴. Since the salt comes from the weak base, we use Kb. Since pKb = 3.44, then. 3.44 = -log(Kb). Thus, Kb = 3.6307×10⁻⁴
KH = Kw/Kb = (x)(x)/(0.51 - x)
1×10⁻¹⁴/ 3.6307×10⁻⁴ = x²/(0.51-x)
x = 3.748×10⁻⁶
Since x from the ICE table is equal to the equilibrium concentration of H+, we can find the pH of the aqueous solution:
pH = -log(H+) = -log(x)
pH = -log ( 3.748×10⁻⁶)
pH = 5.43
Answer:
- The NaCl solution will have higher boiling point.
Explanation:
- C2H6O2 is a molecular substance. Meaning that when it dissolves it will remain this way:
C2H6O2 ---------> C6H12O6 (aq)
- Sodiumchloride (NaCl) is an ionic substance. Meaning that when it dissolves, it will create ions:
NaCl(s)-------> Na+(aq) + Cl- (aq)
Conclusion:
- NaCl is an ionic compound and C2H6O2 is a molecular compound. Ionic compounds have higher boiling points than molecular compounds. Therefore, NaCl will have the higher boiling point.
