Answer:
the volume of a set of keys is 6.75ml
Answer:
0.1388 g
Explanation:
The mass of 
obtained on precipitation = 236 mg
1 mg = 0.001 g
Thus, Mass of = 0.236 g
Molar mass of = 233.43 g/mol
The formula for the calculation of moles is shown below:
Thus,
Moles of = 0.001011 moles
According to the reaction,
Thus, moles of barium = 0.001011 moles
Molar mass of barium = 137.327 g/mol
Thus, Mass = Moles * Molar mass = 0.001011*137.327 g = 0.1388 g
Answer: Combustion Reaction
Explanation: A substance reacts with oxygen
B. The atomic number. This is because the atomic number is the same as the number of protons an element has, and the number of protons defines an element.
Answer:
ΔH= 3KJ
Explanation:
The total heat absorbed is the total energy in the process, and that is in form of entalpy.
ΔH = q + ΔHvap, where q is the heat necessary for elevate the temperature of dietil ether. Suppose the initial temperature is room temperature (25ºC=298 K), then
q= 10g x2.261 J/gK x(310 K - 298K)= 271.32 J= 0.3 kJ
Then
ΔHvap = 10g C4H10O x (1 mol C4H10O/74.12 g C4H10O) x( 15.7 KJ/ 1 mol C4H10O) = 2.12 KJ
ΔH= 2.5KJ ≈ 3KJ
