The number of mole of HCl needed for the solution is 1.035×10¯³ mole
<h3>How to determine the pKa</h3>
We'll begin by calculating the pKa of the solution. This can be obtained as follow:
- Equilibrium constant (Ka) = 2.3×10¯⁵
- pKa =?
pKa = –Log Ka
pKa = –Log 2.3×10¯⁵
pKa = 4.64
<h3>How to determine the molarity of HCl </h3>
- pKa = 4.64
- pH = 6.5
- Molarity of salt [NaZ] = 0.5 M
- Molarity of HCl [HCl] =?
pH = pKa + Log[salt]/[acid]
6.5 = 4.64 + Log[0.5]/[HCl]
Collect like terms
6.5 – 4.64 = Log[0.5]/[HCl]
1.86 = Log[0.5]/[HCl]
Take the anti-log
0.5 / [HCl] = anti-log 1.86
0.5 / [HCl] = 72.44
Cross multiply
0.5 = [HCl] × 72.44
Divide both side by 72.44
[HCl] = 0.5 / 72.4
[HCl] = 0.0069 M
<h3>How to determine the mole of HCl </h3>
- Molarity of HCl = 0.0069 M
- Volume = 150 mL = 150 / 1000 = 0.15 L
Mole = Molarity x Volume
Mole of HCl = 0.0069 × 0.15
Mole of HCl = 1.035×10¯³ mole
<h3>Complete question</h3>
How many moles of HCl need to be added to 150.0 mL of 0.50 M NaZ to have a solution with a pH of 6.50? (Ka of HZ is 2.3 x 10 -5 .) Assume negligible volume of the HCl
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Speed is calculated using the formula distance divided by time. For a distance of 26.2 miles, and a time of 3 hours and 40 minutes, we first convert the time to make it solely in terms of hours. 40 minutes is 2/3 of an hour, so this is a total time of 3 2/3 or 11/3 hours. If we divide 26.2 miles by 11/3 hours, we get a resulting speed of 7.14 miles/hour.
Explanation:
Carbon exists in several isotopes. ... Carbon has the atomic number of 6 which means that all isotopes have the same proton number. However, the number of neutrons is different, thus giving different mass numbers. Carbon-12 has 6 neutrons, carbon-13 has 7 neutrons, and carbon-14 contains 8 neutrons.
d = diameter of the seat = 12 inch
we know that , 1 inch = 0.0254 m
hence
d = diameter of the seat = 12 inch = 12 (0.0254) m = 0.305 m
r = radius of seat = diameter/2 = d/2 = 0.305/2 = 0.1525 m
A = area of seat = πr²
m = mass of the person = 65 kg
g = acceleration due to gravity = 9.8 m/s²
F = force due to weight of person on the seat = mg
pressure on the seat is given as
P = F/A
P = mg/A
P = mg/(πr² )
inserting the values
P = (65 x 9.8)/((3.14) (0.1525)²)
P = 8723.1 N/m²