Answer:
126000J
Explanation:
From the question given, we obtained the following information:
M = 1500g
C = 4.2J/g°C
ΔT = 20°C
Q =?
Q= MCΔT
Q = 1500 x 4.2 x 20 =
Q = 126000J
Answer:
True.
But it only changes in physical change.
How?
Explanation:
The chemical reaction produces a new substance with new and different physical and chemical properties. Matter is never destroyed or created in chemical reactions. The particles of one substance are rearranged to form a new substance.
In a physical change, a substance's physical properties may change.
A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc. ... Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc.
Hope this helps!
Answer:
The answer to your question is molality = 0.61
Explanation:
Freezing point is the temperature at which a liquid turns into a solid if a solute is added to a solution, the freezing point changes.
Data
Kf = 1.86 °C/m
molality = ?
ΔTc = 1.13°C
Formula
ΔTc = kcm
Solve for m
m = ΔTc/kc
Substitution
m = 1.13 / 1.86
Simplification and result
m = 0.61
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of 
= 183.511 g/mole
- First we have to calculate the moles of Cu.
The moles of Cu = 4.7209 moles
From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of = 4.4209 moles
- Now we have to calculate the mass of .
Mass of = Moles of × Molar mass of = 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of = 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
