Answer:
119.7 mL.
Explanation:
- From the general law of ideal gases:
<em>PV = nRT.</em>
where, P is the pressure of the gas.
V is the volume of the container.
n is the no. of moles of the gas.
R is the general gas constant.
T is the temperature of the gas (K).
- For the same no. of moles of the gas at two different (P, V, and T):
<em>P₁V₁/T₁ = P₂V₂/T₂.</em>
- P₁ = 100.0 mmHg, V₁ = 1000.0 mL, T₁ = 23°C + 273 = 296 K.
- P₂ = 1.0 atm = 760.0 mmHg (standard P), V₂ = ??? mL, T₂ = 0.0°C + 273 = 273.0 K (standard T).
<em>∴ V₂ = (P₁V₁T₂)/(T₁P₂) </em>= (100.0 mmHg)(1000.0 mL)(273.0 K)/(296 K)(760.0 mmHg) = 121.4 <em>mL.</em>
Answer:
C. Precipitate the crystals as fast as possible
Explanation:
C. Precipitate the crystals as fast as possible
Precipitation if done fast , can lead to the formation of impure crystals , as impurities also get stuck inside the crystals. So it must be done slowly to obtain the pure crystals . Slower the crystals form , purer they are .
All the other options can lead to a successful recrystallization.
Answer:
Explanation:
When adding or subtracting values, you must round your answer to the same "place" as the measurement with its last significant figure furthest to the left.
That is, you round off to the same number of decimal places as the measurement with the fewest decimal places.
The measurement of 28.1 cm has one digit after the decimal point, so you round the sum to have only one digit to the right of the decimal.
However, the number to be dropped (51) is greater than 5 with only zeros or nothing following the 5.
You must round up the answer. You increase the last significant digit by one.
called the Avogadro number
N(A)= 6.02 x 10^23 mol^-1
1 mole of SO3 will contain 6.02 x 10^23 mol^-1 of SO3 molecules.
thus, 1.14moles will contain;
= 1.14mol x [3mol O/1mol SO3] x [6.02 x 10^23
atoms O/1mol O]
= 2.05884 x 10^24 oxygen atoms
= 1.14mol x [1mol S/1mol SO3] x [6.02 x 10^23
atoms O/1mol O]
= 6.8628 x 10^23 sulfur atoms
hope this helps:-)
