Answer:
density of oxygen = 1.307 g/l
Explanation:
given pressure = 1 atm temperature = 298 k
PM=DRT
where p is pressure M is molecular mass D is density R is gas constant and T is temperature
substituting the values in the equation

D = 1.307 g/l.
a. pH=2.07
b. pH=3
c. pH=8
<h3>Further explanation</h3>
pH=-log [H⁺]
a) 0.1 M HF Ka = 7.2 x 10⁻⁴
HF= weak acid
![\tt [H^+]=\sqrt{Ka.M}\\\\(H^+]=\sqrt{7.2.10^{-4}\times 0.1}\\\\(H^+]=8.5\times 10^{-3}\\\\pH=3-log~8.5=2.07](https://tex.z-dn.net/?f=%5Ctt%20%5BH%5E%2B%5D%3D%5Csqrt%7BKa.M%7D%5C%5C%5C%5C%28H%5E%2B%5D%3D%5Csqrt%7B7.2.10%5E%7B-4%7D%5Ctimes%200.1%7D%5C%5C%5C%5C%28H%5E%2B%5D%3D8.5%5Ctimes%2010%5E%7B-3%7D%5C%5C%5C%5CpH%3D3-log~8.5%3D2.07)
b) 1 x 10⁻³ M HNO₃
HNO₃ = strong acid
![\tt pH=-log[1\times 10^{-3}]=3](https://tex.z-dn.net/?f=%5Ctt%20pH%3D-log%5B1%5Ctimes%2010%5E%7B-3%7D%5D%3D3)
c) 1 x 10⁻⁸ M HCl
![\tt pH=-log[1\times 10^{-8}]=8](https://tex.z-dn.net/?f=%5Ctt%20pH%3D-log%5B1%5Ctimes%2010%5E%7B-8%7D%5D%3D8)
Answer:
The pair of arrows which represents the relationship of speeds of the two cars is;
The second option as shown in the attached drawing
Explanation:
The given parameters are;
The reading on the speedometer of one car = 20 m/s
The reading on the speedometer of the other car = 72 km/h = 20 m/s
The blue arrow = 20 m/s
Therefore, given that the speeds of both cars are equal (20 m/s = 72 km/h = 20 m/s), the pair of arrows that represent the relationship of speeds of the two cars is two equal length blue arrows which is the second option
The attached diagram showing the pair of arrows that represents the relationship of speeds of the two cars is drawn using Microsoft Visio.
Answer:
Sodium fluoride is a colorless crystalline solid or white powder, or the solid dissolved in a liquid. It is soluble in water. It is noncombustible.(I got this answer from g o o g l e)
Explanation: