Answer:
0,171 M NaCl and 0,168 m NaCl
Explanation:
Molarity (M) is an unit of chemical concentration that relates moles of solute per liters of solution and molality (m) is another unit of chemical concentration that relates moles of solute per kg of solution.
For a solution of 10g/L of NaCl the molarity is:
10g/L NaCl×
= 0,17 moles/L of NaCl≡ 0,171 M NaCl
For molality you can know that in 1 L you have 0,17 moles of NaCl.
The kg of solution are:
0,010 kg of NaCl (solute) + 1 kg of solvent (Water, 1L of water is 1 kg) = 1,01 kg of solution.
Thus, molality of 10 g/L NaCl solution is:
= 0,168 m NaCl
I hope it helps!
Answer:
4.22 mol H₂O
Explanation:
Step 1: Write the equation for the synthesis of water
2 H₂ + O₂ ⇒ 2 H₂O
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of O₂ to H₂O is 1:2.
Step 3: Calculate the moles of water produced from 2.11 moles of oxygen
We will use the previously established molar ratio.
2.11 mol O₂ × 2 mol H₂O/1 mol O₂ = 4.22 mol H₂O
Answer:
3.1 L
Explanation:
Step 1: Given data
- Mass of oxygen (m): 3.1 g
Step 2: Calculate the moles of oxygen
The molar mass of oxygen is 32.00 g/mol.
Step 3: Calculate the volume of the container
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 0.097 mol × (0.0821 atm.L/mol.K) × 390 K / 1.00 atm
V = 3.1 L
Answer:
If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
In this way, between heat and temperature there is a direct proportional relationship (Two magnitudes are directly proportional when there is a constant so that when one of the magnitudes increases, the other also increases; and the same happens when either of the two decreases .). The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature, ΔT= Tfinal - Tinitial
In this case:
- Q= 27 kJ= 27,000 J (being 1 kJ=1,000 J)
- m=700 g
- ΔT= Tfinal - Tinitial= Tfinal - 90 °C
Replacing:
Solving:
16.125 °C= Tfinal - 90 °C
Tfinal= 16.125 °C + 90 °C
Tfinal= 106.125 °C
<u><em>If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C</em></u>
