Q = mcΔθ
67.5 = m x 0.45 x (28.5 - 21.5)
M = 67.5 / 3.15
= 21.4 g
Answer:

Explanation:
1. Take in account the sulfuric acid at STP:

2. Density is expressed as the ratio between the mass and the volume of a substance so:

Solving for m:

3. Replace values:


<h2>
Answer: START (2)</h2>
Explanation:
AUG is a <u>START</u> codon. (2)
A start codon is the first codon translated by a ribosome. It usually produces an amino acid that initiates the producyion of a polypeptide chain.
Answer:
e) pH is independent of concentration.
Explanation:
a) It is a mixture of a weak acid and its conjugate base. <em>TRUE. </em>A buffer is defined as a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid.
b) Resists pH changes because it reacts with added acid or base. <em>TRUE. </em>Thermodynamically, the reaction of added acid or base is faster with the buffer mixture than with H⁺ or OH⁻ ions of the solutions.
c) The maximum buffer capacity is at pH = pKa. <em>TRUE. </em>The buffer capacity is pka±1. For this, buffer capacity is maximum in pka.
d) pH is dependent on the solution ionic strength and temperature. <em>TRUE.</em> Ionic strength and temperature are factors that influence concentrations of ions in solutions as the H⁺ ion that is the responsible
e) pH is independent of concentration. <em>FALSE. </em>pH in a buffer depends completely of concentrations of the acid and its conjugate base or vice versa.
I hope it helps!
Answer:
The density is 1,35 g/cm3
Explanation:
We use the formula for calculate the density
δ =m/V =12,2g / 9,0 cm3= 1,35 g/cm3