5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
2.469 could be maid dont forget to hit that thanks button
D. Changes
Hope this helps :)
Answer:
-26.125 kj
Explanation:
Given data:
Mass of water = 250.0 g
Initial temperature = 30.0°C
Final temperature = 5.0°C
Amount of energy lost = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 5.0°C - 30.0°C
ΔT = -25°C
Specific heat of water is 4.18 j/g.°C
Now we will put the values in formula.
Q = m.c. ΔT
Q = 250.0 g × 4.18 j/g.°C × -25°C
Q = -26125 j
J to kJ
-26125 j ×1 kj /1000 j
-26.125 kj
