Answer:
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Explanation:
when the molten outer core cools and become solid ,a very long time in future,the earth's magnetic field will disappear
Answer:
W = -120 KJ
Explanation:
Since the piston–cylinder assembly undergoes an isothermal process, then the temperature is constant.
Thus; T1 = T2 = 400K
change in entropy; ΔS = −0.3 kJ/K
Formula for change in entropy is written as;
ΔS = Q/T
Where Q is amount of heat transferred.
Thus;
Q = ΔS × T
Q = -0.3 × 400
Q = -120 KJ
From the first law of thermodynamics, we can find the workdone from;
Q = ΔU + W
Where;
ΔU is Change in the internal energy
W = Work done
Now, since it's an ideal gas model, the change in internal energy is expressed as;
ΔU = m•C_v•ΔT
Where;
m is mass
C_v is heat capacity at constant volume
ΔT is change in temperature
Now, since it's an isothermal process where temperature is constant, then;
ΔT = T2 - T1 = 0
Thus;
ΔU = m•C_v•ΔT = 0
ΔU = 0
From earlier;
Q = ΔU + W
Thus;
-120 = 0+ W
W = -120 KJ
the balanced chemical equation representing the reaction between represent sodium metal (Na) and chlorine gas (cl2) is as below
2 Na + Cl2→ 2 NaCl
2 moles of sodium metal ( Na) reacted with 1 mole of gas chlorine gas (cl2) and 2 moles of sodium chloride (NaCl)
Answer: D. It reacts with oxygen in the presence of moist air.
Explanation:
The element Gold, does not react with oxygen,hence it is not affected by corrosion,neither does it rust.
A balanced chemical equation for this reaction :
FeS(s)+2HCl(aq)→FeCl2(aq)+ H2S(g)
<h3>Further explanation</h3>
Given
Word equation
Required
Balanced equation
Solution
The chemical equation can be expressed in terms of:
- word equation
- skeleton equation
- balanced equation
Skeleton equation
FeS(s)+ HCl(aq) --> FeCl2 (aq) + H2S (g)
Balanced equation
FeS(s)+2HCl(aq)→FeCl2(aq)+ H2S(g)
