Answer:
12.99
Explanation:
<em>A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.</em>
Step 1: Given data
- Mass of KOH: 716. mg (0.716 g)
- Volume of the solution: 130. mL (0.130 L)
Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
The balanced chemical reaction is:
<span>3N2H4(l)→4NH3(g)+N2(g)
</span>
The amounts given for the N2H4 reactant will be the starting point for our calculations.
2.6mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 3.47 mol NH3
4.05mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 5.4 mol NH3
63.8g N2H4 <span>( 4 mol NH3 / 3 mol N2H4 ) = 85.07 mol NH3</span>
Salt: NaCl
Hydrogen gas: H2
Answer your lookin for is 27.
Apartheid was a legal racial separation system that ruled the Republic of South Africa from 1948 to 1993. Apartheid's mechanisms were in place before its creation, and South Africa is still dealing with these issues. Apartheid divided various races into different regions, and discrimination against people of color was not only acceptable, but also legal, with white people having full priority on housing, jobs, education, and political power. Even though South Africa was constantly chastised for the system, it wasn't until 1991 that the legal system of apartheid began to crumble, and it was finally brought down in 1993.
What is Apartheid?
Apartheid has been legally abolished, but whites and blacks continue to coexist in separate communities. There are still "black" and "white" neighborhoods, as well as "black" and "white" churches and restaurants. When the international media writes about Southern Africa, they almost always mention the country's "fading rainbow" and experiment in multi-ethnic democracy .
To learn more about Apartheid from the given link:
brainly.com/question/3811942
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