Answer:
25.8
Explanation:
Let's write the reaction between magnesium-phosphide and potassium:
Mg3P2 + K = Mg + K3P
And now let's balance this equation:
Mg3P2+6K=3Mg+2K3P
We see that the ratio of magnesium-phosphide and potassium is 1:6, which means that for every mole of magnesium-phosphide there need to be 6 moles of potassium.
Since we have 4.3 moles of Mg3P2, there need to be 6 • 4.3 = 25.8 moles of potassium.
Answer:
pH = 8.34
Explanation:
The equilbriums of the amphoteric HCO₃⁻ (Ion of NaHCO₃) are:
H₂CO₃ ⇄ <em>HCO₃⁻</em> + H⁺ Ka1 <em>-Here, HCO₃⁻ is acting as a base-</em>
<em>HCO₃⁻</em>⇄ CO₃²⁻ + H⁺ Ka2 <em>-Here, is acting as an acid-</em>
Where Ka1 = 4.3x10⁻⁷ and Ka2 = 4.8x10⁻¹¹. As pKa = -log Ka:
pKa1 = 6.37; pKa2 = 10.32
As the pH of amphoteric salts is:
pH = (pKa1 + pKa2) / 2
<h2>pH = 8.34</h2>
Hydrophilic;
Polar compounds
water
ions
glucose
Hydrophobic;
Triglycerides
cholesterol
Lipids
Oil
Carbohydrates
<h3>What are hydrophilic substances?</h3>
The term hydrophilic substances is used to describe the substances that could dissolve in water. They are those substances that are water soluble. Somehow, the substances must be polar because in chemistry like dissolves like.
The hydrophobic substances are those substances that do not dissolve in water. They are nonpolar and interact with other nonpolar substances.
The classification of the substances took place below;
Hydrophilic;
Polar compounds
water
ions
glucose
Hydrophobic;
Triglycerides
cholesterol
Lipids
Oil
Carbohydrates
Learn more about hydrophilic substances:brainly.com/question/4692308
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Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011% Pb by mass. 13.6 × 10³ ml water contains 150 mg of Pb.
<h3>How to calculate the mass of solution ? </h3>
Given percentage of Pb present in the sample solution is 0.0011%
That means 0.0011 grams of Pb present in the 100g of solution.
So,
= 
= 13.6 × 10³ g water
<h3>What is Density ? </h3>
The mass per unit volume is called density. Density is represented as D or ρ.
It is expressed as:

where,
ρ = Density
m = mass of the object
V = Volume of object
Now put the value in above expression we get


V = 13.6 × 10³ ml
Thus from the above conclusion we can say that Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011% Pb by mass. 13.6 × 10³ ml water contains 150 mg of Pb.
Learn more about the Density here: brainly.com/question/1354972
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