Answer:
actually answer should be helium
Answer:
The answer is option a. The evaporation of water from the skin
Explanation:
An endothermic reaction is any synthetic reaction that retains heat from its environment. The ingested energy gives the enactment energy to the reaction to happen.
No new bonds formed, no bonds broken in this example. water molecules go from liquid to vapour (gas ), intermolecular bond exist between polar (-OH) molecules and energy is required to break these bonds during the change from liquid to gas. So, it is endothermic .
Remaining three above examples are exothermic. combustion of gas releases energy(exothermic). burninig of the candle exothermic because the energy released from the oxygen into carbon dioxide and water.oxidation of iron also exothermic
Answer: Mass of silver deposited at the cathode is 37.1g
Explanation: According to Faraday Law of Electrolysis, the mass of substance deposited at the electrode (cathode or anode) is directly proportional to quantity of electricity passed through the electrolyte
Faraday has found that to liberate one gm eq. of substance from an electrolyte, 96500C of electricity is required.
+e− ==> Ag(s)
Given that
Current (I) = 8.5A
Time (t) = 65 *60 = 3900s
Quantity of electricity passed = 8.5*3900 =33150C
Molar mass of Ag= 108g
96500C will liberate 108g
33150C will liberate Xg
Xg= (108*33150)/96500
=37.1g
Therefore the mass of Ag deposited at the cathode is 37.1g.
Answer:
ΔT = 76.5 °C
Explanation:
Given data:
Amount of water = 100.0 g
Energy needed = 32000 J
Change in temperature = ?
Solution,
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Now we will put the values in formula.
Q = m.c. ΔT
ΔT = Q / m.c
ΔT = 32000 j/ 100.0 g × 4.184 j/g. °C
ΔT = 32000 j / 418.4 j /°C
ΔT = 76.5 °C
Answer:
H₂O
Explanation:
Chemical equation:
C₅H₁₂ + O₂ → CO₂ + H₂O
Balanced chemical equation:
C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O
The given reaction is combustion reaction. The balance equation shows that there are equal number of moles of carbon, hydrogen and oxygen on both side of equation thus it follows the law of conservation of mass.
Combustion reaction:
The reaction in which substance react with oxygen and produced carbon dioxide and water.
Mostly hydrocarbons burns in the presence of oxygen and form carbon dioxide and water.
