First, calculate for the amount of heat used up for increasing the temperature of ice.
H = mcpdT
H = (18 g)*(2.09 J/g-K)(50 K) = 1881 J
Then, solve for the heat needed to convert the phase of water.
H = (1 mol)(6.01 kJ/mol) = 6.01 kJ = 6010 J
Then, solve for the heat needed to increase again the temperature of water.
H = (18 g)(4.18 J/gK)(70 k)
H = 5266.8 J
The total value is equal to 13157.8 J
Answer: 13157.8 J
Both <span>b) the weight of jelly beans and c) elevation of a person on a ramp</span>
Answer: The half-reactions represents reduction are as follows.
Explanation:
A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element takes place is called reduction-half reaction.
For example, the oxidation state of Cr in 
is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.
Similarly, oxidation state of Mn in 
is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.
Thus, we can conclude that half-reactions represents reduction are as follows.
Answer:
0.0468 g.
Explanation:
- The decay of radioactive elements obeys first-order kinetics.
- For a first-order reaction: k = ln2/(t1/2) = 0.693/(t1/2).
Where, k is the rate constant of the reaction.
t1/2 is the half-life time of the reaction (t1/2 = 1620 years).
∴ k = ln2/(t1/2) = 0.693/(1620 years) = 4.28 x 10⁻⁴ year⁻¹.
- For first-order reaction: <em>kt = lna/(a-x).</em>
where, k is the rate constant of the reaction (k = 4.28 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = t1/2 x 8 = 1620 years x 8 = 12960 year).
a is the initial concentration (a = 12.0 g).
(a-x) is the remaining concentration.
∴ kt = lna/(a-x)
(4.28 x 10⁻⁴ year⁻¹)(12960 year) = ln(12)/(a-x).
5.54688 = ln(12)/(a-x).
Taking e for the both sides:
256.34 = (12)/(a-x).
<em>∴ (a-x) = 12/256.34 = 0.0468 g.</em>
It takes the Earth 24 hours to rotate on its axis and this rotation is what causes there to be days and nights.
