Answer:
44.6millilitres
Explanation:
Using the general gas law equation as follows:
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
V1 = initial volume (L)
T1 = initial temperature (K)
P2 = final pressure (atm)
V2 = final volume (L)
T2 = final temperature (K)
According to this question;
V1 = 30mL
T1 = 273K (STP)
P1 = 1 atm (STP)
V2 = ?
T2 = 300K
P2 = 75.0 kPa = 75 × 0.00987 = 0.74atm
Using P1V1/T1 = P2V2/T2
1 × 30/273 = 0.74×V2/300
30/273 = 0.74V2/300
Cross multiply
300 × 30 = 273 × 0.74V2
9000 = 202.02V2
V2 = 9000/202.02
V2 = 44.55
V2 = 44.6millilitres.
Answer:
The freezing point of the solution is -1.4°C
Explanation:
Freezing point decreases by the addition of a solute to the original solvent, <em>freezing point depression formula is:</em>
ΔT = kf×m×i
<em>Where Kf is freezing point depression constant of the solvent (1.86°C/m), m is molality of the solution (Moles CaBr₂ -solute- / kg water -solvent) and i is Van't Hoff factor.</em>
Molality of the solution is:
-moles CaBr₂ (Molar mass:
189.9g ₓ (1mol / 199.89g) = 0.95 moles
Molality is:
0.95 moles CaBr₂ / 3.75kg water = <em>0.253m</em>
Van't hoff factor represents how many moles of solute are produced after the dissolution of 1 mole of solid solute, for CaBr₂:
CaBr₂(s) → Ca²⁺ + 2Br⁻
3 moles of ions are formed from 1 mole of solid solute, Van't Hoff factor is 3.
Replacing:
ΔT = kf×m×i
ΔT = 1.86°C/m×0.253m×3
ΔT = 1.4°C
The freezing point of water decreases in 1.4°C. As freezing point of water is 0°C,
<h3>The freezing point of the solution is -1.4°C</h3>
<em />
The quantities you have to know are the molar masses and the molecular stoichiometric ratios. The solution for this problem is as follows:
Mass Percent of Iodine = (Mass of Iodine/Mass of NaBr and KI)*100
Mass of NaBr = 1 mol NaBr * 102.89 g/mol = 102.89 g
Mass of KI = 0.3 mol KI * 166 g/mol = 49.8 g
Mass of KI = 0.3 mol KI * 1 mol I/1mol KI * 1 mol I₂/2 mol I * 253.81 g/mol = 38.07 g
Mass %I₂ = 38.07/(102.89+49.8) * 100 = <em>24.9%</em>
Answer: Combination reaction
Explanation:
Hydrogen (H2) combines with nitrogen (N2) to form a single compound, ammonia (NH3) in a combination reaction.
The chemical equation is as follows:
N2(g) + 3H2(g) --> 2NH3(g)