Answer is: 6,16 kJ.
1) changing temperature of ice from -25°C to 0°C.
Q₁ = m·C·ΔT
Q₁ = 18 g · 2 J/g·°C · 25°C
Q₁ = 900 J.
m(H₂O) = 1mol · 18 g/mol = 18 g.
C - <span>specific heat of ice.
</span>2) changing temperature of water from 0°C to 70°C.
Q₁ = m·C·ΔT
Q₁ = 18 g · 4,18 J/g·°C · 70°C
Q₁ = 5266,8 J.
C - specific heat of water.
Q = Q₁ + Q₂ = 900 J + 5266,8 J
Q = 6166,8 J = 6,16 kJ.
We should describe a little bit the legend.
A - Element - we should have circles with same color and not bonded together (argon gas).
B - Compound - here we may have circles with same or different color bonded together (water or oxygen which is a diatomic molecule).
C - Mixture of elements - circles with different colors not not bonded together (mixture of noble gases).
D - Mixture of compounds - circles with same or different color bonded together but we should see two or more types of connectivity between circles (mixture of water and ethanol).
E - Mixture of elements and compounds - circles with same or different color bonded together mixed with circles with same color and not bonded together (a mixture between oxygen which is a diatomic molecule and noble gas like argon).
Now we may answer the question:
1) B
2) C
3) D
4) D
5) A
6) B
7) B
8) E
9) E
10) D
11) B
12) D
13) D
14) D
15) D
Answer:
I think the answer is
2) They have the same number of valence electrons
The answer is (3) moles of solute per liter of solution. That is what the definition of molarity of a solution means. The equation is concentration = mol number of solute/ volume of solution.
