The heat released by the substance in the calorimeter is equal to the heat absorbed by water which results to the decrease and increase in temperature, respectively.
We use m Cp ΔT to balance the heat involved
(m Cp ΔT) subs in calorimeter = <span>(m Cp ΔT) water
</span>125 g * Cp * (97.0-23.5 ) C = 250 g *(4.18 J/C g)* (23.5-20)
Cp = 0.398 J/Cg
Answer is B
To calculate the molarity you only need to know the number of moles in the solution and the volume of that solution. This exercise gives both and with that you divide moles by volume(usually in liters).
500 ml equals 0,5 L
molarity= number of moles/ volume
molarity=0,75 x 0,5
= 0,375 mol/L
an atom that has 18 protons, 18 neutrons and 20 neutrons. This atom has mass number of 38
mass number is calculated as number of protons + number on neutrons
therefore the mass number of the atom = 18+20= 38
Since the atom has a electronic configuration of 2.8.8,the atom cannot be negatively or positively charged because it is stable.
The atomic number of the atom is 18 since atomic number is equal to number of protons
3H + 3Br = HBr9 Organic chemistry mechanism