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Naddika [18.5K]
2 years ago
14

What is known about a reaction with a positive enthalpy?

Chemistry
1 answer:
MariettaO [177]2 years ago
8 0

Answer: C

Explanation:

In endothermic reactions, enthalpy is positive, and in exothermic reactions, enthalpy is negative, So, if enthalpy is positive, then it is an endothermic reaction, and hence is required for the reaction to occur.

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Why the bond in water molecule os polar covalent bond, while than in chlorine molecule is pure covalent bond? Give reason? ​
erastovalidia [21]

Explanation:

The unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that a water molecule has two poles - a positive charge on the hydrogen pole (side) and a negative charge on the oxygen pole (side). We say that the water molecule is electrically polar.

8 0
3 years ago
Calculate the number of molecules in a deep breath of air whose volume is 2.15 L at body temperature, 37 ∘C, and a pressure of 7
Zinaida [17]
PV = nRT 
R = 0.0821 L * atm / mol * K 
(ideal gas constant) 

First, convert 735 torr to atm. Divide by 760. 
(1 atm = 760 torr) 

735 torr * 1 atm / 760 torr = 0.967 atm 
Then, convert 37 C to Kelvin. Just add 273. 
37 C = 310K 

n = PV / RT 
= (0.967)(2.07) / (0.0821)(310) 
= 0.0786 mol 

<span>0.0786 mol * 6.02 * 10^23 molecules / 1 mol = 4.73 * 10^22 molecules </span>
7 0
3 years ago
Read 2 more answers
. What is a carbonyl group? Draw the carbonyl groups that are characteristic of aldehydes, ketones, carboxylic acids, and esters
Elan Coil [88]

Answer :

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Carboxylic group : It is the class of organic compound in which the carboxylic (-COOH) group is attached to a hydrocarbon is known as carboxylic.

The general formula of carboxylic is, C_nH_{2n+1}COOH. According to the IUPAC naming, the carboxylic are named as alkanoic acids.

Aldehyde group : It is the class of organic compound in which the (-CHO) group is attached to a hydrocarbon is known as aldehyde.

The general representation of aldehyde is, R-CHO. According to the IUPAC naming, the aldehyde are named as alkanals.

Ketone group : It is the class of organic compound in which the (-CO) group is directly attached to the two alkyl group of carbon is known as ketone.

The general representation of ketone is, R-CO-R^'. According to the IUPAC naming, the ketone are named as alkanone.

Ester group : It is the class of organic compound in which the (-COO) group is directly attached to the two alkyl group of carbon is known as ester.

The general representation of ester is, R-COO-R^'. According to the IUPAC naming, the ester are named as alkyl alkanoate.

6 0
3 years ago
Nitrogen (N) has an atomic number of 7 and an atomic mass of 14. Which of the following correctly shows the electron arrangement
bonufazy [111]

Answer:

2, 5

Explanation:

3 0
3 years ago
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Which of the following is not a type of mechanical wave?
Otrada [13]
Concave is not a type of mechanical wave because it doesn’t need a medium for propagation.
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