Hello!
The number of 20-g ice cubes required to absorb 47 kJ from a glass of water upon melting is 7 icecubes
Why?
We are going to clear from the equation of the released heat, the mass of ice (m). The specific latent heat of fusion of ice is 336 kJ/kg:

So, 7 ice cubes are required to absorb that amount of heat from the glass of water.
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Answer:
Water does not remain when an insoluble substance is added
Answer:
Water pressure 0.5 atm
Total Pressure= 2.27 atm
Explanation:
To answer this problem, one has to realize that there are two processes that increase the temperature of the sealed vessel.
First, the dry air in the sealed vessel will be heated which will cause its pressure to increase and it can be determined by the equation:
P₁ x T₂ = P₂ x T₁ ∴ P₂ = P₁ x T₂ / T₁
For the second process, we have an amount of n moles of water which will be released when the copper sulfate is heated. In this case, to determine the value of the the water gas we will use the gas law:
PV = nRT ∴ P = nRT/V
n will we calculated from the quantity of sample.
2.50 g CuSo₄ 5H₂O x 1 mol/ 249.69 g = 0.01 mol CuSo₄ 5H₂O
the amount water of hydration is
= 0.01 mol CuSo₄ 5H₂O * 5 mol H₂O / 1 mol CuSo₄ 5H₂O
= 0.05 mo H₂O
pressure of dry air at the final temperature,
P₂ = 1 atm x 500 K/ 300 K = 1.67 atm
Pressure of water :
P (H₂O) 0.05 mol x 0.08206 Latm/kmol x 500 K/ 4 L = 0.5 atm
∴ Total Pressure = 1.67 atm
H2O Pressure = 0.5 atm
First there is a need to calculate the molar mass of Ba(NO₃)₂:
137.3 + 2 (14.0) + 6 (16) = 261.3 grams/mole
The molar mass, denoted by M in chemistry refers to a physical characteristic illustrated as the mass of a given component divided by the amount of the component. The molar masses are always denoted in grams/mole.
After finding the molar mass, the number of moles can be identified as:
432 grams / 261.3 g/mol = 1.65 moles of Ba(NO₃)₂.
Between phosphorous, sulfur, chlorine and argon, argon is the element that's the least likely to form an ionic bond with sodium.