<span>C.) add salt to the fresh water
if an egg sinks to the bottom in a container of fresh water, you can add salt to the fresh water to make the egg float.</span>
Answer:
117.3 W is being removed.
Explanation:
The heat removed can be calculated as:
Q = m*c*ΔT
Where m is the mass, c is the specific heat and ΔT is the temperature variation. Because there're two components:
Q = mwater*cwater*ΔT + maluminum*caluminum*ΔT
Q = (mwater*cwater + maluminum*caluminum)*ΔT
Searching in a thermodynamic table:
cwater = 4.184 J/g°C
caluminium = 0.9 J/g°C
In 1 minute, the temperature decreases 2.2°C, so ΔT = -2.2°C
Q = (700*4.184 + 300*0.9) * (-2.2)
Q = -7037.36 J
The rate of energy is the potency (P), which is the heat divided by the time. So, for 1 minute (60 s):
P = -7037.36/60
P = -117.3 J/s
P = -117.3 W
The minus signal indicates that the energy is being removed.
Answer:
V₂ = 123.6 L
Explanation:
According to Boyle's law pressure and volume of a gas are inversely related if amount and temperature are kept constant. For the initial and final states the gas law is given as,
P₁ V₁ = P₂ V₂ ----- (1)
Data Given;
P₁ = 103 kPa
V₁ = 30 L
P₂ = 25 kPa
V₂ = ?
Solution:
Solving equation 1 for V₂,
V₂ = P₁ V₁ / P₂
Putting values,
V₂ = (103 kPa × 30 L) ÷ 25 kPa
V₂ = 123.6 L
Result:
As the pressure is decreased from 103 kPa to 25 kPa, therefore, volume has increased from 30 L to 123.6 L.
The given question is incomplete. The complete question is :
What volume of 0.160 M solution of KOH must be added to 550.0 mL of the acidic solution to completely neutralize all of the 0.150 M hydrochloric acid?
Answer: Volume in liters to three significant figures is 0.516 L
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH
We are given:
Putting values in above equation, we get:
(1L=1000ml)
Thus volume in liters to three significant figures is 0.516 L
