Answer:
a) Endothermic
b) T₂ = 53.1 ºC
Explanation:
a) We are told that when the ammonium nitrate dissolves in water the pack gets cold so the system is absorbing heat from the surroundings and by definition it is an endothermic process.
b) Recall that the heat, Q, is given by the formula:
Q = mcΔT where m is the mass of water,
c is the specific heat of water, and
ΔT is the change in temperature
We can determine the value for Q since we are given the heat of solution for the ammonium nitrate. From there we can calculate ΔT and finally answer our question.
Molar mass NH₄NO₃ = 80.04 g/mol
moles NH₄NO₃ = 50.0 g/ 80.04 g/mol = 0.62 mol
Q = 25.4 kJ/mol x 0.62 mol = 15.87 kJ = 15.87 kJ x 1000 J = 1.59 x 10⁴ J
Q = mcΔT ⇒ ΔT = Q/mc
ΔT = 1.59 x 10⁴ J/ (135 g x 4.184 J/gºC ) = 28.1 ºC
T₂- T₁ = ΔT ⇒ T₂ = ΔT + T₁ = 28.1 ºC +25.0 ºC = 53.1 ºC
According to the density of the liquid, we can get the mass of liquid is 70*0.85=59.5 g. So the total mass is 59.5+60.75=120.25 g.
Q, R, S, P is the order of apparent magnitude of the stars, starting from the least to the greatest.
Answer: Q, R, S, P
<u>Explanation:</u>
The apparent magnitudes of the star is the brightness calculated by an observer at a particular distance from the Earth. The smaller the distance between the star and the Earth, the greater the apparent brightness.
So , from the given distance (in light years), Q,R,S,P is the answer (least to the greatest apparent magnitude) (distance is greatest to least).
Answer:
Do not incinerate "why the gas in the gas is initially at 23degree and 360kPa and the can has a volume of 350Ml
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