Answer:
68.97g of milk must be added
Explanation:
To solve this problem we need to use the equation:
Q = C*m*ΔT -Coffee cup calorimeter equation-
This equation relates mass and change in temperature with heat of solution, Q.
The energy that decreases in the milk is the same that increases in the milk. That is:
Q(milk) = Q(tea)
Using the equation:
4.184J/molK* Mass milk * (65.0°C - 7.00°C) = 4.184J /molK * 200g (Tea) * (85.0°C - 65.0°C)
Mass milk * 58.0°C = 200g * 20.0°C
Mass milk = 4000g°C / 58.0°C
Mass milk =
68.97g of milk must be added
The balanced equation for the reaction is as follows
Na₂CO₃ + 2HCl --> 2NaCl + CO₂ + H₂O
stoichiometry of Na₂CO₃ to HCl is 1:2
number of Na₂CO₃ moles reacted = molarity x volume
number of Na₂CO₃ moles = 0.100 mol/L x 0.750 L = 0.0750 mol
according to molar ratio of 1:2
1 mol of Na₂CO₃ reacts with 2 mol of HCl
then 0.0750 mol of Na₂CO₃ mol reacts with - 2 x 0.0750 = 0.150 mol
molarity of given HCl solution is 1.00 mol/L
molarity is defined as the number of moles of solute in 1 L of solution
there are 1.00 mol in 1 L of solution
therefore there are 0.150 mol in - 0.150 mol / 1.00 mol/L = 0.150 L
volume of HCl required is 0.150 L
Answer:
An engineer that designs buildings is a structural engineer.
Hope this helps.
Answer:
VSEPR theory
Explanation:
The valence shell electron pair repulsion theory was propounded by Gillespie and Nylom (1957).
The entire idea of the VSEPR theory is that the shape of a molecule depends on the electrostatic repulsion between electron pairs surrounding the central atom in a molecule which causes these pairs to be separated as far as possible.
The shapes of many molecules can be accurately predicted based on this model.
Answer:
The heat absorbed by the sample of water is 3,294.9 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
The sensible heat of a body is the amount of heat received or transferred by a body when it undergoes a temperature variation (Δt) without there being a change of physical state (solid, liquid or gaseous). Its mathematical expression is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case:
- Q=?
- m= 45 g
- c= 4.184
- ΔT= Tfinal - Tinitial= 38.5 C - 21 C= 17.5 C
Replacing:
Q= 4.184 * 45 g* 17.5 C
Solving:
Q=3,294.9 J
<u><em>The heat absorbed by the sample of water is 3,294.9 J</em></u>
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