Answer:
Explanation:
Using freezing point depression formula,
ΔTemp.f = Kf * b * i
Where,
ΔTemp.f = temp.f(pure solvent) - temp.f(solution)
b = molality
i = van't Hoff factor
Kf = cryoscopic constant
= 1.86°C/m for water
= (0 - (-5.58))/1.86
= 3.00 mol/kg
Assume 1 kg of water(solvent)
= (3.00 x 1)
= 3.00 mol.
Answer: n=15.56moles
Explanation:
PV = nRT
where
P is pressure in atmospheres
V is volume in Liters
n is the number of moles of the gas
R is the ideal gas constant = given as (0.0821L -atm/k-mol
PV = nRT
n= PV/RT
n= (1.5 X 230)/ (0.0821 X 270)
n= 15.56 moles
Answer:
Vertebrates, invertebrates, and amphibians.
Explanation:
Vertebrates have backbones. Frogs have back bones.
Invertebrates do not have backbones. Hermit crabs do not have back bones.
Amphibians are cold-blooded vertebrate animals. Frogs are cold-blooded vertebrate animals.
Precipitation occurs when the product of the ion concentration exceeds the Ksp.
The reaction between Na2S and CuSO4 will give us the balanced chemical reaction of,
Na2S + CUSO4 --> Na2SO4 + CuS
This means that for every 78g of Na2S, there needs to be 159.6 g of CuSO4. The ratio is equal to 0.4887 of Na2S: 1 of CuSO4. Thus, for every 12.1g of CuSO4, we need only 5.91 g of Na2S. Thus, there is an excess of 9.58 g of Na2S. The answer is letter C.
