Answer:- 64015 J
Solution: There is 4250 mL of water in the calorimeter at 22.55 degree C.
density of water is 1 g per mL.
So, the mass of water = 
= 4250 g
Final temperature of water after adding the hot copper bar to it is 26.15 degree C.
So, 
for water = 26.15 - 22.55 = 3.60 degree C
Specific heat for water is 4.184 
The heat gained by water is calculated by using the formula:
where, q is the heat energy, m is mass and c is specific heat.
Let's plug in the values in the formula and do the calculations:
q = 64015 J
So, 64015 J of heat is gained by the water.
Answer:
Explanation:
<u>1) Data:</u>
a) n = 2 moles
b) T = 373 K
c) V = 2.5 liter
d) P = ?
<u>2) Chemical principles and formula</u>
You need to calculate the pressure of the propane gas in the mixture before reacting. So, you can apply the partial pressure principle which states that each gas exerts a pressure as if it occupies the entire volume.
Thus, you just have to use the ideal gas equation: PV = nRT
<u>3) Solution:</u>
P = 2 mol × 0.08206 atm-liter /K-mol × 373K / 2.5 liter = 24.5 atm
Since the number of moles are reported with one significant figure, you must round your answer to one significant figure, and that is 20 atm (20 is closer to 24.5 than to 30).
Answer : The molar concentration of ethanol in the undiluted cognac is 8.44 M
Explanation :
Using neutralization law,
where,
= molar concentration of undiluted cognac = ?
= molar concentration of diluted cognac = 0.0844 M
= volume of undiluted cognac = 5.00 mL = 0.005 L
= volume of diluted cognac = 0.500 L
Now put all the given values in the above law, we get molar concentration of ethanol in the undiluted cognac.
Therefore, the molar concentration of ethanol in the undiluted cognac is 8.44 M
To determine the time it takes to completely vaporize the given amount of water, we first determine the total heat that is being absorbed from the process. To do this, we need information on the latent heat of vaporization of water. This heat is being absorbed by the process of phase change without any change in the temperature of the system. For water, it is equal to 40.8 kJ / mol.
Total heat = 40.8 kJ / mol ( 1.50 mol ) = 61.2 kJ of heat is to be absorbed
Given the constant rate of 19.0 J/s supply of energy to the system, we determine the time as follows:
Time = 61.2 kJ ( 1000 J / 1 kJ ) / 19.0 J/s = 3221.05 s
Answer:
1.505×10^23 atoms of lead
Explanation:
Volume of lead in the lungs = total volume of lungs = 5.60L
1 mole = 22.4L
5.6L of lead = 5.6/22.4 = 0.25 mole
From Avogadro's law
1 mole of lead contains 6.02×10^23 atoms of lead
0.25 mole of lead = 0.25×6.02×10^23 = 1.505×10^23 atoms of lead
