Answer:

Explanation:
The two requirements for a measurement are a <u>number</u> and a <u>unit.</u>
For example, here is a measurement:
38.6 cm
The <u>number</u> is 38.6 and the <u>unit</u> is cm, or centimeters.
Therefore, both <em>number </em>and <em>unit</em> are correct.
Answer:

Explanation:
The pressure is constant, so we can use Charles' Law to calculate the volume.

Data:
V₁ = 693 mL; T₁ = 45 °C
V₂ = ?; T₂ = 150 °C
Calculations:
(a) Convert temperature to kelvins
T₁ = ( 45 + 273.15) = 318.15 K
T₂ = (150 + 273.15) = 423.15 K
(b) Calculate the volume

Answer:
pH = 7.8
Explanation:
The Henderson-Hasselbalch equation may be used to solve the problem:
pH = pKa + log([A⁻] / [HA])
The solution of concentration 0.001 M is a formal concentration, which means that it is the sum of the concentrations of the different forms of the acid. In order to find the concentration of the deprotonated form, the following equation is used:
[HA] + [A⁻] = 0.001 M
[A⁻] = 0.001 M - 0.0002 M = 0.0008 M
The values can then be substituted into the Henderson-Hasselbalch equation:
pH = 7.2 + log(0.0008M/0.0002M) = 7.8
Lava I think try that hope it helps :)
Answer:
d) A - 70% B - 30%
Explanation:
If x is the abundance of A, and 1−x is the abundance of B, then:
x (32.0) + (1−x) (33.0) = 32.3
32x + 33 − 33x = 32.3
33 − x = 32.3
x = 0.7
The abundance of A is 70%, and the abundance of B is 30%.