Answer:
Explanation:
we know that
ΔH=m C ΔT
where ΔH is the change in enthalpy (j)
m is the mass of the given substance which is water in this case
ΔT IS the change in temperature and c is the specific heat constant
we know that given mass=2.9 g
ΔT=T2-T1 =98.9 °C-23.9°C=75°C
specific heat constant for water is 4.18 j/g°C
therefore ΔH=2.9 g*4.18 j/g°C*75°C
ΔH=909.15 j
Calculate the mass of the solute <span>in the solution :
Molar mass KCl = </span><span>74.55 g/mol
m = Molarity * molar mass * volume
m = 0.9 * 74.55 * 3.5
m = 234.8325 g
</span><span>To prepare 0.9 M KCl solution, weigh 234.8325 g of salt in an analytical balance, dissolve in a beaker, shortly after transfer with the help of a funnel of transfer to a volumetric flask of 100 cm</span>³<span> and complete with water up to the mark, then cover the balloon and finally shake the solution to mix
hope this helps!</span>
Answer:
earth surface is uneven because land heats faster than water causes air to warm.,expand and rise over land while it cools and sinks over the cooler waters surface..
Answer:
Final temperature: 659.8ºC
Expansion work: 3*75=225 kJ
Internal energy change: 275 kJ
Explanation:
First, considering both initial and final states, write the energy balance:
Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:
The pressure is constant, so: 
(There is a multiplication by 100 due to the conversion of bar to kPa)
So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):
On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:
Subtracting the first from the second:
Isolating 
:
Assuming that it is water steam, n=0.1666 kmol
ºC
<span>NPK ratio system is a conventional shorthand for the ratio of the nitrogen N), phosphorus (P) and potassium (K) in a fertilizer. It actually shows amount of P</span>₂O₅.
If we use 100 kg of P₂O₅:
m(P₂O₅) = 0,15 · 100 kg.
m(P₂O₅) = 15 kg.
m(P₂O₅) : M(P₂O₅) = m(P) : 2M(P).
15 kg : 142 = m(P) : 62.
m(P) = 6,55 kg.
ω(P) = 6,55 kg ÷ 100 kg · 100% = 6,55%.
