Answer:
Precise but not accurate.
Explanation:
We can tell the performance of the balance is precise, because the repeated measurements give values close to one another.
However, the performance of the balance is not accurate, as the mean value of the repeated measurements (195.587) is not close to the value considered as true (in this case the standard calibration mass with a certified value of 200.002 g).
Answer:
Change in volume on changing temperature from 33
to 5 is 5.49 mL
Explanation:
Initial volume of gas = V = 60 mL
Assuming final volume of gas to be V' mL
Initial temperature = T = 33 = 306 K
Final temperature = T' = 5 = 278 K
The relationship between volume and temperature of gas at constant pressure is shown below
Change in volume on changing temperature = 5.49 mL
Answer:
(a) 13.7 g.
(b) 28.91 g.
Explanation:
- molality (m) is the no. of moles of solute dissolved in 1.0 kg of solvent.
∴ m = (no. of moles of solute)/(mass of water (kg))
<em>∴ m = (mass/molar mass of solute)/(mass of water (kg)).</em>
<em />
<u><em>(a) Calculate the mass of CaCl₂·6H₂O needed to prepare 0.125 m CaCl₂(aq) by using 500. g of water.</em></u>
∵ m = (mass/molar mass of CaCl₂·6H₂O)/(mass of water (kg)).
m = 0.125 m, molar mass of CaCl₂·6H₂O = 219.0757 g/mol, mass of water = 500.0 g = 0.5 kg.
∴ 0.125 m = (mass of CaCl₂·6H₂O / 219.0757 g/mol)/(0.5 kg).
∴ mass of CaCl₂·6H₂O = (0.125 m)(219.0757 g/mol)(0.5 kg) = 13.7 g.
<u><em>(b) What mass of NiSO₄·6H₂O must be dissolved in 500. g of water to produce 0.22 m NiSO₄(aq)?</em></u>
∵ m = (mass/molar mass of NiSO₄·6H₂O)/(mass of water (kg)).
m = 0.22 m, molar mass of NiSO₄·6H₂O = 262.84 g/mol, mass of water = 500.0 g = 0.5 kg.
∴ 0.125 m = (mass of NiSO₄·6H₂O / 262.84 g/mol)/(0.5 kg).
∴ mass of NiSO₄·6H₂O = (0.22 m)(262.84 g/mol)(0.5 kg) = 28.91 g.
The heat in particles travels through convection at a certain speed depending on what density a mass has.
<span>Answer:
(16.2 g C2H6O2) / (62.0678 g C2H6O2/mol) / (0.0982 kg) = 3.9704 mol/kg = 3.9704 m
a.)
(3.9704 m) x (1.86 °C/m) = 7.38 °C change
0.00°C - 7.38 °C = - 7.38 °C
b.)
(3.9704 m) x (0.512 °C/m) = 2.03 °C change
100.00°C + 2.03 °C = 102.03 °C</span>
