Answer:
1.Begin energy in kilojoules.
2.Use a conversion factor in convert kilojoules to joules .
3.Use a conversion factor top convert
Answer:
a. Ag+ and Ca2+
The pair of cations related to the question are as below:
a. Ag+ and Ca2+
b. Hg2^2+ and Ag^+
c. Ba^2+ and Na^+
d. Ca^2+ and Ba^2+
e. Pb^2+ and Ag^+
Explanation:
a. Ag+ and Ca2+ correct
Ag+ will precipitate with dilute hydrobromic acid (HBr) but Ca+2 will not
Ag+ + Br- -----------------> AgBr (s)
Ca+2 + 2Br- ---------------> CaBr2 (aq)
B) Hg2^2+ and Ag^+ Incorrect
Both Hg2^2+ and Ag^+ will precipitate. One has to precipitate while the other does not, so this is incorrect.
C) Ba2 and Na+ both won't precipitate. Incorrect
One has to precipitate while the other does not, so this is incorrect.
D) Ca2+ and Ba 2+both won't precipitate. Incorrect
One has to precipitate while the other does not, so this is incorrect.
E ) Both Pb2 and Ag+ will precipitate. Incorrect
One has to precipitate while the other does not, so this is incorrect.
Answer:
12.5g
Explanation:
1. Percentage of solution = 5.
2. Mass of solution = 250g.
3. = Mass of solute / 250 x 100.
4. = 5 x 250 / 100.
5. = 12.5g.
Answer:
Temperature increase = ΔT = 2.08 °C
Explanation:
Given data:
Energy absorbed by plant = 4200 J
Specific heat capacity of soil = 0.84 J/g°C
Mass of soil = 2400 g
How much temperature increase = ?
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
by putting values,
4200 J = 2400 g ×0.84 J/g°C × ΔT
4200 J = 2016 J/°C × ΔT
ΔT = 4200 J / 2016 J/°C
ΔT = 2.08 °C
Answer:
True
Explanation:
Theories are not laws and so new scientific evidence could render them as untrue. For example, the big bang theory on how the universe has started is just a theory. Current evidence backs it up, but if future evidence disproves it, the theory will be replaced by a different one.