Answer : The correct option is, 
Explanation :
Amino acid : The acid that contains two functional groups that are carboxylic group,
and ammine group,
.
When the two or more that two amino acids join together with the help of peptide bond, they produces polypeptide chain or protein.
The bond present between the two amino acid is called a peptide bond.
The peptide bond is a chemical bond that is formed between the two molecules when the nitrogen of one amino acid react with the carbon of another amino acid by releasing a water molecule. This is a dehydration synthesis or condensation reaction.
From this we conclude that, only two functional groups carboxylic group,
and ammine group,
are present in all amino acids.
Hence, the correct option is, 
To find the answer you can set up an equation like this: 3(x)(d)
x would stand for number of cans each dog eats, while d stands for the number of days in a week. 3(2)(7)=42 Sam would have to purchase 42 cans of dog food each week.
Answer : The mole fraction of NaCl in a mixture is, 0.360
Explanation : Given,
Moles of
= 7.21 mole
Moles of
= 9.37 mole
Moles of
= 3.42 mole
Now we have to calculate the mole fraction of
.

Now put all the given values in this formula, we get:

Therefore, the mole fraction of NaCl in a mixture is, 0.360
Answer: theres no image or claim