Δ H reaction = q / n where q: amount of heat released and n is number of moles of substance.
q = m . C . ΔT where:
m = mass of substance (g)
C = Specific heat capacity (4.18)
ΔT = change in temperature = 24.25 - 23.16 = 1.09
q = 1000 x 4.18 x 1.09 = 4556 J = 4.556 kJ
number of moles (n) = Molarity (M) x Volume (L)
= 0.185 M x 0.07 L = 0.01295 mole
Δ H = q / n = - (4.556 kJ / 0.01295 mole) = -351.8 kJ / mol
Note: it is exothermic reaction (-ve sign) i.e. temperature is raised
You cannot create something from nothing and similarly you cannot create less from more, if you didn't balance an equation that needs to be balanced, your product might end up equalling more or less than the total mass of the two elements combined. Which is impossible
<span>1. Which of the following does NOT indicate that a chemical change may have taken place?
A. fracture formation
B. gas production
C. precipitate formation
D. energy transfer
it is (a.)</span>
Answer:Vrms is 149.7266 m/sec
Explanation:The root means square velocity of a gas can be calculated as follows:
Vrms =

where:
R is the ideal gas constant = 8.3145
T is absolute temperature = -55 + 273 = 118 degrees kelvin
M is the molar mass of the gas = 131.293 grams = 0.131293 kg
Substituting with these givens in the above equation, we would find that the Vrms is 149.7266 m/sec
Hope this helps :)
Because density=mass/volume, the density of a substance would increase if the mass was increased and the volume was not, and decreased if the volume was increased and the mass was not.