Answer:
The correct answer is -0.129 kJ
Explanation:
In the given case, the cooling of the balloon is done by withdrawing 0.784 J of heat, and the work done by the atmosphere on the balloon is 655 J. First, there is a need to transform kJ into J, 1 kJ = 1000 J. So, 0.784 kJ would be 784 J.
The ΔE or the change in the internal energy can be calculated by using the formula, ΔE = q + w ----- (1).
In the given case, q refers to the heat moved out of the system, that is, the value of q would be less than 0 or will be a negative quantity. Therefore, the heat moved out of the system will be -784 J. On the other hand, as the work or w is done on the system, therefore, the value of w would be more than 0 or will be a positive quantity. Thus, the value of w will be +655 J.
Now putting the values in the equation (1) we get,
ΔE = -784 J + 655 J
ΔE = -129 J or -0.129 kJ
As the change in internal energy comes out to be a negative value, therefore, the process is considered exothermic.
<em>Answer:</em>
- Organic compounds are those which are derivatives of hydrocarbons. They are classified into following functional groups.
<em>Alkane: </em>
- Alkane are simplest hydrocarbons.
- They have general formula CnH2n+2. These hydrocarbons contain single bond.
- For example ethane , H3C----CH3.
<em>Alkene:</em>
- Alkene are most reactive.
- They have general formula CnH2n.
- These contain double bond in their structure.
- For example , ethene, H2C=CH2
<em>Alkyne:</em>
- These are less less reactive as compare to alkenes.
- They have general formula CnH2n-2.
- They contain triple bonds in their structure.
- For example Acetylene HC≡CH
<em>Alcohol:</em>
Alcohol have functional group OH. They have general formual R---OH, R may be alkyl group.For example Ethanol H3CH2C---OH
<em>Amine:</em>
- Amine contain NH2 F.G.
- They have general formula R---NH2.
- There are three types of amine like primary, secondary and tertiary amine.
- For example H3CH2C---NH2
<em>Aldehyde:</em>
- Aldehydes have CHO F.G .
- They have general formula R--CHO.
- For example H3CH2C---CHO
<em>Ketone:</em>
- Ketones have R--CO--R functional group.
- For example acetone H3C---CO---CH3
<em>Carboxylic acid:</em>
- They functional group COOH.
- Their general formula is R---COOH.
- For example Acetic acid H3C---COOH
Answer:
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Explanation:
Answer : The final temperature of the solution in the calorimeter is,
Explanation :
First we have to calculate the heat produced.
where,
= enthalpy change = 82.8 kJ/mol
q = heat released = ?
m = mass of = 5.10 g
Molar mass of = 110.98 g/mol
Now put all the given values in the above formula, we get:
Now we have to calculate the final temperature of solution in the calorimeter.
where,
q = heat produced = 3.80 kJ = 3800 J
m = mass of solution = 100 + 5.10 = 105.10 g
c = specific heat capacity of water =
= initial temperature =
= final temperature = ?
Now put all the given values in the above formula, we get:
Thus, the final temperature of the solution in the calorimeter is,
The formula is m = D x V
D = <span>13.69 g/cm^3.
</span>V = <span>15.0 cm^3
the mass of the liquid mercury is m= </span>13.69 g/cm^3 x 15.0 cm^3 = 195g
the molar mass of Hg is 200,
1 mole of Hg = 200g Hg, so #mole of Hg= 195 / 200 = 0.97 mol
but we know that
1 mole = 6.022 E23 atoms
0.97 mole=?
6.022 E23 atoms x 0.97 / 1 mole = 5.84 E23 atoms