The air temperature in a sealed, insulated box.. 20°C An ice cube at O'C is
placed in the box where it slowly melts. How and why does the melting of the ice
affect the air temperature in the box?
Melting is endothermic so the air temperature increases
Melting is exothermic, so the air temperature decreases
Melting is endothermic, so the air temperature decreases
Melting is exothermic, so the air temperature increases
Answer:
Melting is endothermic, so the air temperature decreases.
Explanation:
Hello there!
In this case, according to the given statement, it is possible to infer that the ice is melt because energy is applied to the ice and thereafter its temperature increases; this is possible because the joined particles of a solid substance need energy to undergo such a separation that they become more far away to each other and therefore transcend to the liquid phase due to the new molecules arrangement. Thus, the answer is Melting is endothermic, so the air temperature decreases because as the ice heats up, the air cools down as it gives it energy to the ice.
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1.20×10−8s to nanoseconds
Answer:
There are 12 nanoseconds in [tex]1.2\times 10^{-8}\ s[/tex].
Explanation:
We need to convert [tex]1.2\times 10^{-8}\ s[/tex] to nanoseconds.
We know that,
[tex]1\ s=10^9\ ns[/tex]
Now using unitary method to solve it such that,
[tex]1.2\times 10^{-8}\ s=1.2\times 10^{-8}\ \times 10^9\\\\=1.2\times 10\\\\=12\ ns[/tex]
So, there are 12 nanoseconds in [tex]1.2\times 10^{-8}\ s[/tex].
How many joules of energy are required to vaporize 13.1 kg of lead at its normal boiling point?
Answer: 1123000 Joules of energy are required to vaporize 13.1 kg of lead at its normal boiling point
Explanation:
Latent heat of vaporization is the amount of heat required to convert 1 mole of liquid to gas at atmospheric pressure.
Amount of heat required to vaporize 1 mole of lead = 177.7 kJ
Molar mass of lead = 207.2 g
Mass of lead given = 1.31 kg = 1310 g (1kg=1000g)
Heat required to vaporize 207.2 of lead = 177.7 kJ
Thus Heat required to vaporize 1310 g of lead =[tex]\frac{177.7}{207.2}\times 1310=1123kJ=1123000J[/tex]
Thus 1123000 Joules of energy are required to vaporize 13.1 kg of lead at its normal boiling point
Consider the reaction, C2H4(g) + H2(g) - C2H6(8), where AH = -137 kJ. How many kilojoules are released when 3.5 mol of CH4
reacts?
480 kJ are released
20 x 103 kJ are released
570 kJ are released
137 kJ are released
Answer: 480 kJ of energy is released when 3.5 mol of [tex]C_2H_4[/tex] reacts.
Explanation:
The balanced chemical reaction is:
[tex]C_2H_4(g)+H_2(g)\rightarrow C_2H_6(g)[/tex] [tex]\Delta H=-137kJ[/tex]
Thus it is given that the reaction is exothermic (heat energy is released) as enthalpy change for the reaction is negative.
1 mole of [tex]C_2H_4[/tex] on reacting gives = 137 kJ of energy
Thus 3.5 moles of [tex]C_2H_4[/tex] on reacting gives = [tex]\frac{137}{1}\times 3.5=480 kJ[/tex] of energy
Thus 480 kJ of energy is released when 3.5 mol of [tex]C_2H_4[/tex] reacts.
Is a cold and b is warm? Please help
Answer:
Label A shows cold area on the mug, while label B shows a warm area.
Explanation:
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What causes the lines in the spectrum for elements
Which compound contains three elements?
A. Aluminium chloride
B. iron(III) oxide
C. potassium oxide
D. sodium carbonate
Answer:
Sodium Carbonate
Explanation:
Sodium carbonate is made of three elements, that are, sodium, carbon and oxygen.
Its formula is Na2CO3.
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