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:
0.6522 mol/L.
Explanation:
<em>Molarity is defined as the no. of moles of a solute per 1.0 L of the solution.</em>
<em />
M = (no. of moles of solute)/(V of the solution (L)).
<em>∴ M = (no. of moles of solute)/(V of the solution (L)) </em>= (1.5 mol)/(2.3 L) = <em>0.6522 mol/L.</em>
Answer:
OH^-
Explanation:
Any substance that is able to neutralize acidity in the stomach is generally known as an antacid. There are various kinds of antacids that are in common use. It should be noted that the stomach is usually slightly acidic.
Milk of magnesia is the substance magnesium hydroxide with chemical formula Mg(OH)2. A solution of milk of magnesia contains Mg^2+ and OH^-.
Hence the negative ion contained in milk of magnesia is the hydroxide ion OH^-.
Answer:
0.189 g.
Explanation:
- This problem is an application on <em>Henry's law.</em>
- Henry's law states that the solubility of a gas in a liquid is directly proportional to its partial pressure of the gas above the liquid.
- Solubility of the gas ∝ partial pressure
- If we have different solubility at different pressures, we can express Henry's law as:
<em>S₁/P₁ = S₂/P₂,</em>
S₁ = 0.0106/0.792 = 0.0134 g/L and P₁ = 0.321 atm
S₂ = ??? g/L and P₂ = 5.73 atm
- So, The solubility of the gas at 5.73 atm (S₂) = S₁.P₂/P₁ = (0.0134 g/L x 5.73 atm) / (0.321 atm) = 0.239 g/L.
<em>The quantity in (g) = S₂ x V = (0.239 g/L)(0.792 L) = 0.189 g.</em>
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Answer:
substance is related to the average kinetic energy of the particles of that substance
Explanation: