Answer:
The amount/type of stain
Explanation:
You would want to ensure that the stain was the same in both samples.
Answer:
b) 3.10
Explanation:
HF ⇄ H
+ + F
Using Henderson-Hasselbalch Equation:
pH = pKa + log [A-]/[HA].
Where;
pKa = Dissociation constant = -log Ka
Hence, pKa of HF = -log 7.2 x 10^-4 = 3.14266
[A-] = concentration of conjugate base after dissociation = moles of base/total volume
= 0.15 x 0.3/0.8
= 0.05625 M
[HA] = concentration of the acid = moles of acid/total volume
= 0.10 x 0.5/0.8
= 0.0625 M
Note: <em>Total volume = 500 + 300 = 800 mL = 0.8 dm3</em>
pH = 3.14266 + log [0.05625/0.0625]
= 3.14267 + (-0.04575749056)
= 3.09691250944
<em>From all the available options below:</em>
<em>a) 2.97
</em>
<em>b) 3.10
</em>
<em>c) 3.19
</em>
<em>d) 3.22
</em>
<em>e) 3.32</em>
The correct option is b.
1, When temperature is increased the volume will also increase. this is because the particles will gain kinetic energy and bombard the walls of the container of the gas at a higher frequency, therefore, for the pressure to remain constant as per Charles' law, the volume will have to increase so that the rate of bombardment remains constant. This is explained by the Charles law which states that the volume of a gas is directly proportional to the absolute temperature provided pressure remains constant.
2. When temperature is Decreased the volume will also Decrease. this is because the particles will loose kinetic energy and bombard the walls of the container of the gas less frequently, therefore, for the pressure to remain constant as per Charles' law, the volume will have to reduce so that the rate of bombardment remains constant. This is explained by the Charles law which states that the volume of a gas is directly proportional to the absolute temperature provided pressure remains constant.
3. When temperature is increased the pressure will increase. This is because the gas particles gain kinetic energy and bombard the walls of the container more frequently. this is according to Pressure law which states that for a constant volume of a gas the pressure is directly proportional to absolute temperature
4. When temperature is decreased, pressure will decrease, This is because the gas particles lose kinetic energy and bombard the walls of the container less frequently. this is according to Pressure law which states that for a constant volume of a gas the pressure is directly proportional to absolute temperature
5. When particles are added, pressure will increase. This is because the bombardment per unit area also increases. Boyles law explains this, that at fixed temperature the volume of a gas is inversely proportional to the pressure.
6. When particles are removed, the pressure will decrease. This is because the bombardment per unit area also decreases. Boyle's law explains this, that at fixed temperature the volume of a gas is inversely proportional to the pressure.
So for D you have to find energy right
from c you get wavelength Lambda
so on D use this
E = Hc / lambda
c is given 1.5 x 10 ^20
h = 6.624 x 10^-34
and then you get answer for energy
Answer:
Explanation:
Num of molecules = num of moles * Avogadro's constant (6.02* 10^23)
But num of moles = reacting mass / molar mass
Molar mass of H20= 2*1 + 16 = 2+16 = 18g
Reacting mass of H20 = 0.55g
Therefore, num of moles of H20 = 0.55g/18g = 0.031 moles
Therefore, num of molecules of H20 = 0.031 * 6.02*10^23
= 1.87*10^22 molecules of H20
