When ice melts, the physicals state changes from solid to liquid. The energy or the heat required (q) required to change a unit mass (m) of a substance from solid to liquid is known as the enthalpy or heat of fusion (ΔHf). The variables; q, m and ΔHf are related as:
q = m * ΔHf
the mass of ice m = 65 g
the heat of fusion of water at 0C = ΔHf = 334 J/g
Therefore: q = 65 g * 334 J/g = 21710 J
Now:
4.184 J = 1 cal
which implies that: 21710 J = 1 cal * 21710 J/4.184 J = 5188.8 cal
Hence the heat required is 5188.8 cal or 5.2 Kcal (approx)
Answer:
C. AlCl3 is a covalent compound.
Explanation:
It is formed by mutual sharing of electrons between two atoms each contributing equal number of electrons to the electron pair.
Answer:
9.1 mol
Explanation:
The balanced chemical equation of the reaction is:
CO (g) + 2H2 (g) → CH3OH (l)
According to the above balanced equation, 2 moles of hydrogen gas (H2) are needed to produce 1 mole of methanol (CH3OH).
To convert 36.7 g of hydrogen gas to moles, we use the formula;
mole = mass/molar mass
Molar mass of H2 = 2.02g/mol
mole = 36.7/2.02
mole = 18.17mol
This means that if;
2 moles of H2 reacts to produce 1 mole of CH3OH
18.17mol of H2 will react to produce;
18.17 × 1 / 2
= 18.17/2
= 9.085
Approximately to 1 d.p = 9.1 mol of methanol (CH3OH).
Crush the limestone... it would give more area for the acid to react
