²³⁵₉₂U → ²³¹₉₀Th + ⁴₂He
D) ²³¹₉₀Th
Answer: 17.78g
Explanation:
Assume there is no heat exchange with the environment, then the amount of heat taken by the steel rod, Q(s), is equal to the amount of heat lost by the water, Q(w), but with opposite sign.
Q(s) = -Q(w)
Remember, Q = mc(ΔΦ)
Where Q = amount of heat
m = mass of steel
c = specific heat capacity of steel
ΔΦ = Initial temperature T1 - Final temperature T2
Q = mc(T1-T2)
Recall, Q(s) = -Q(w). Then,
m(s)*c(s)*(T1s - T2s) = - m(w)*c(w)*(T1w - T2w)
Substituting each values
Note: m(w) = volume of water*density = 75mL*1g/mL = 75g
m(s)*0.452*(21.5-2) = -75*4.18*(21.5-22)
m(s)*8.814 = 156.75
m(s) = 156.75/8.814
m(s) = 17.78g
Therefore, the mass of steel is 17.78g
Answer:
CH3COO-
Explanation:
The conjugate base if a weak acid is a strong base, and the conjugate base of a strong acid is a weak base.
Acetic acid is a weak acid, so its conjugate base (CH3COO-) is a strong base.
Nitric, sulfuric, and hydrochloric acids are all strong acid. Their conjugate bases (NO3-, SO4^2-, and Cl- are all weak bases.
Answer:
The pure crystals were soluble in the wash solvent.
Explanation:
The pure crystals on the funnel dissolved because they were soluble in the solvent used for washing. They were carried into the filter flask by the solvent.
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