The number of moles that are contained in the given mass of propane (
is 1.7143 moles.
<u>Given the following data:</u>
- Mass of propane = 75.6 grams.
<u>Scientific data:</u>
- The molar mass of propane = 44.1 g/mol.
To calculate the number of moles that are contained in the given mass of propane ():
<h3>How to calculate the moles of a compound.</h3>
In this exercise, you're required to determine the number of moles of propane that are contained in the given sample:
Mathematically, the number of moles contained in a chemical compound is given by this formula:
Substituting the given parameters into the formula, we have;
Number of moles = 1.7143 moles.
Read more on number of moles here: brainly.com/question/3173452
Answer: b
explanation: i had the question on a test and got it right.
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
Learn more about pH of buffer:
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<span>Answer : B. hope it helped</span>
Proton = +1
neutron = 0
electron = -1
