Answer:
a. Heat is often absorbed during reactions.
c. Heat is often released during chemical reactions.
Explanation:
Thermochemistry -
The study of thermochemistry involve the change in the amount of heat , during any physical or chemical process , is referred to as thermodynamics .
The focus of thermochemistry is on the changing amount of energy in the form of heat , on the system with respect to the surroundings .
The process like boiling , melting , sublimation , may require energy or releases energy , and hence are studied under thermochemistry .
Hence , from the given question ,
The correct options are - a , c.
N=m/M
n=118/58.93=2
Answer: 2 moles
Percent error is the difference between the measured and known value, divided by the known value, multiplied by 100%.
So first, we take our measured value, .299 cm, minus our known value, .225 cm.
.299 cm - .225 cm=.004 cm
Next, we divide that by our known value
Finally, multiply your answer by 100
.0177777778 x 100= 1.77777778 %
Round to three significant figures, and you're done.
=1.78 % error
Solute=potassium chloride, solvent=water
Solution is here,
for initial case,
temperature(T1)=70°C=70+ 273=343K
vloume( V1) =45 L
for final case,
temperature( T2)=?
volume(V2)= 91.3 L
at constant pressure,
V1/V2 = T1/T2
or, 45/91.3 = 343/ T2
or, T2= (343×91.3)/45
or, T2=695.9 K = (695.9-273)°C=422.9°C
