When the concentration is expressed in molality, it is expressed in moles of solute per kilogram of solvent. Since we are given the mass of the solvent, which is water, we can compute for the moles of solute NaNO3.
0.5 m = x mol NaNO3/0.5 kg water
x = 0.25 mol NaNO3
Since the molar mass of NaNO3 is 85 g/mol, the mass is
0.25 mol * 85 g/mol = 21.25 grams NaNO3 needed
To answer this question, you need to know how to convert milliliters into liter then into a gallon. In this question, you are given the gasoline density (0.737g/ml) and the volume (12.8gallon). The information is enough to determine the gas weight. The calculation would be:
Gas weight= density * volume
Gas weight= 0.737g/ml * 12.8 gal * 3.78L/gal * 1000ml/L= 35659.008 grams
The total change in internal energy would simply be
calculated using the formula:
ΔU = -P (V2 – V1) + ΔH
where ΔU is the change in internal energy; P is constant
pressure = 30 atm = 3,039,750 Pa; V2 is final volume = 2 L = 0.002 m^3; V1 is
initial volume = 7.20 L = 0.0072 m^3; while ΔH is the heat = -74,400 J (heat
released so negative)
Therefore:
ΔU =-3,039,750 Pa * (0.002 m^3 - 0.0072 m^3) + (- 74,400
J)
<span>ΔU = - 58,593.3 J = - 58.6 kJ</span>
Because pure silicon is a perfect semiconductor.
For room temperature, it rarely conducts, you can search for the threshold temperature, the characteristic equation is fairly complicated.
Answer:
13 chromosomes, meiosis
Explanation:
the sperm cell contributes half of the chromosome in an offspring while the egg cells contributes the other half. Hence, the sperm cell has half of 26, 13. This process is called meiosis. Meiosis is when one cell undergoes cell division twice, thus creating 4 new cells. Each of these 4 new cells have half the amount of chromosomes as the original cell.
