Answer:
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<em><u>Durban, South Africa</u></em></h2>
Explanation:
please mark as brain and like please
Q = mCpΔT —> Solve for Cp —> Cp = q/mΔT
q = -6700 J (negative because it released heat
m = 70 g
ΔT = Final temp - initial temp = 25 - 90 = -65°C
Cp = -6700 J / (70 g)(-65°C) = 1.47 J/g°C
Explanation:
Le Chatelier's principle states that for a long period of time if a system is at equilibrium and it is subjected to change in concentration, temperature, volume or pressure then the system shifts to a new equilibrium.
This change will partly counter acts the applied change.
Therefore, when heat is added to the system then equilibrium will shift to the side where temperature or heat is reduced again.
For example, 
Since heat is added to the system, hence, system will shift to the left side or we can say equilibrium will shift to the backward direction.
Since the configuration contains the number 2s and 2p, you can assume that it is in period 2 of the periodic table. By noble gas shorthand, you start with helium, which is atomic number 2. 2s²2p^4 has 2+4 = 6 valence
Add 2+6 = 8, which is Oxygen.
Answer:
The answer is 1.06g.
Explanation:
Analysis of question:
1. Identify the information in the question given.
- volume of HCl is 2 dm3
- pH of HCl is 2.0
2. What the question want?
- mass of Na2CO3 is ?(unknown)
- 3. Do calculation.
- 1st-Write a balanced chemical equation:
Na2CO3 + 2HCl (arrow) 2NaCl + H20 + CO2
- 2nd-Determine the molarity of HCl with the value of 2.0.
pH= -log[H+]
2.0= -log[H+]
log[H+]= -2.0
[H+]= 10 to the power of negative 2(10-2)
=0.01 mol dm-3
molarity of HCl is 0.01 mol dm-3
- 3rd-Find the number of moles of HCl
n=MV
=0.01 mol dm-3 × 2 dm3
=0.02 mol of HCl
- 4th-Find the second mol of it.
Based on the chemical equation,
2.0 mol of HCl reacts with 1.0 mol of Na2CO3
0.02 mol of HCl reacts with 0.01 mol of Na2CO3
<u>N</u><u>a</u>2CO3>a=<u>1</u><u> </u>mol
<u>2</u><u>H</u>Cl>b=<u>2</u><u> </u>mol
mass= number of mole × molar mass
g=0.01 × [2(23)+ 12+ 3(16)]
g=0.01 × 106
# =1.06 g.
