Answer:
the answer is B, "summer, winter"
Answer:
The approximate molar enthalpy of combustion of this substance is -66 kJ/mole.
Explanation:
First we have to calculate the heat gained by the calorimeter.
where,
q = Heat gained = ?
c = Specific heat = 
ΔT = The change in temperature = 3.08°C
Now put all the given values in the above formula, we get:
Now we have to calculate molar enthalpy of combustion of this substance :
where,
= enthalpy change = ?
q = heat gained = 8.2544kJ
n = number of moles methane = 
Therefore, the approximate molar enthalpy of combustion of this substance is -66 kJ/mole.
Answer:
b. 485 kPa
Explanation:
Gay-Lussac's law express that the pressure of a gas under constant volume is directly proportional to the absolute temperature. The equation is:
P1T2 = P2T1
<em>P is pressure and T absolute temperature of 1, initial state and 2, final state of the gas</em>
<em>Where P1 = 74psi</em>
<em>T2 = 20°C + 273.15 = 293.15K</em>
<em>P2 = ?</em>
<em>T1 = (95°F -32) * 5/9 + 273.15 = 308.15K</em>
<em />
Replacing:
74psi*293.15K = P2*308.15K
70.4psi
In kPa:
70.4psi * (6.895kPa / 1psi) =
<h3>b. 485 kPa
</h3>
The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
Answer:
b
Explanation:
the baloon is made to hold more air.
