<u>Answer:</u> The concentration of ethyl ethanoate at equilibrium is 
<u>Explanation:</u>
Given values:
Equilibrium concentration of ethanol = 
Equilibrium concentration of ethanoic acid = 

The given chemical equation follows:

The expression of
for above equation follows:
![K_c=\frac{[C_2H_5OH][CH_3COOH]}{[CH_3COOC_2H_5]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BC_2H_5OH%5D%5BCH_3COOH%5D%7D%7B%5BCH_3COOC_2H_5%5D%7D)
Putting values in above expression, we get:
![0.27=\frac{0.42\times 0.42}{[CH_3COOC_2H_5]}](https://tex.z-dn.net/?f=0.27%3D%5Cfrac%7B0.42%5Ctimes%200.42%7D%7B%5BCH_3COOC_2H_5%5D%7D)
![[CH_3COOC_2H_5]=\frac{0.42\times 0.42}{0.27}=0.653mol/dm^3](https://tex.z-dn.net/?f=%5BCH_3COOC_2H_5%5D%3D%5Cfrac%7B0.42%5Ctimes%200.42%7D%7B0.27%7D%3D0.653mol%2Fdm%5E3)
Hence, the concentration of ethyl ethanoate at equilibrium is 
Answer:
(a) Ala; (b) Tyr; (c) Ser; (d) His
Explanation:
The general formula for an amino acid is NH₂-CH(R)-COOH
The differences among the different amino acids is caused by the side groups R.
(a) Ala, Leu
Ala: R = CH₃-
Leu: R = (CH₃)₂CHCH₂-
Leucine has a larger hydrophobic side group. It should be the less soluble of the pair,
Alanine is the more soluble amino acid.
(b) Tyr, Phe
Tyr: R = HOC₆H₄CH₂-
Phe: R = C₆H₅CH₂-
Tyrosine has a polar OH group. It can form hydrogen bonds with water.
Tyrosine is the more soluble amino acid.
(c) Ser, Ala
Ser: R = HOCH₂-
Ala: R = CH₃-
Serine has a polar OH group. It can form hydrogen bonds with water.
Serine is the more soluble amino acid.
(d) Trp, His
Trp: R = Indole-CH₂-
His: R = Imidazole-CH₂-
Tryptophan has a large aromatic hydrophobic side chain.
Histidine is a basic amino acid. At pH 7 it exists mainly as the anion NH₂CHRCOO⁻, which is hydrophilic.
Histidine is the more soluble amino acid.
Answer:
= 20.82 g of BaCl2
Explanation:
Given,
Volume = 200 mL
Molarity = 0.500 M
Therefore;
Moles = molarity × volume
= 0.2 L × 0.5 M
= 0.1 mole
But; molar mass of BaCl2 is 208.236 g/mole
Therefore; 0.1 mole of BaCl2 will be equivalent to;
= 208.236 g/mol x 0.1 mol
= 20.82 g
Therefore, the mass of BaCl2 in grams required is 20.82 g
Because usually when Ba forms ion it will form Ba2+. But when Fe forms ion, it can form Fe2+ or Fe3+. So you need to distinguish them by add their valence at the name.
Explanation:
For the given equation:
NH3 + HCl -> NH4Cl
This is an acid-base reaction (neutralization): NH3 is a base, HCl is an acid and NH4Cl is the sal.
Answer: b) NH3 is the base and NH4CI is the salt.