Answer:
K2X
Explanation:
Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.
MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.
Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1
Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X
Answer:
The volume of mercury-contaminated water that has to be consumed to ingest 0.100 g mercury is 2.50 × 10⁴ l
Explanation:
Hi there!
First, let´s convert 0.100 g to mg:
0.100 g · (1000 mg/1 g) = 100 mg
The contaminated water has 0.004 mg per liter, then, we have to find the volume of water that contains 100 mg of mercury:
100 mg · (1 l / 0.004 mg) = 2.50 × 10⁴ l
Then, the volume of mercury-contaminated water ( at a concentration of 0.004 mg/l) that has to be consumed to ingest 0.100 g mercury is 2.50 × 10⁴ l
Have a nice day!
Answer:
The answer to your question is 7160 cm
Explanation:
Data
diameter = 1 mm
length = ?
amount of gold = 1 mol
density = 17 g/cm³
Process
1.- Get the atomic mass of gold
Atomic mass = 197 g
then, 197g ------------ 1 mol
2.- Calculate the volume of this wire
density = mass/volume
volume = mass/density
volume = 197/17
volume = 5.7 cm³
3.- Calculate the length of the wire
Volume = πr²h
solve for h
h = volume /πr²
radius = 0.05 cm
substitution
h = 5.7/(3.14 x 0.05²)
h = 5.7 / 0.0025
h = 7159.2 cm ≈ 7160 cm
Answer:
- 0.0249% Sb/cm
Explanation:
Given that:
One surface contains 1 Sb atom per 10⁸ Si atoms and the other surface contains 500 Sb atoms per 10⁸ Si atoms.
The concentration gradient in atomic percent (%) Sb per cm can be calculated as follows:
The difference in concentration = 
The distance 
= 0.2-mm = 0.02 cm
Now, the concentration of silicon at one surface containing 1 Sb atom per 10⁸ silicon atoms and at the outer surface that has 500 Sb atom per 10⁸ silicon atoms can be calculated as follows:
= - 0.0249% Sb/cm
b) The concentration 
of Sb in atom/cm³ for the surface of 1 Sb atoms can be calculated by using the formula:
Lattice parameter = 5.4307 Å; To cm ; we have
= 
= 
The concentration 
of Sb in atom/cm³ for the surface of 500 Sb can be calculated as follows:
= 
= 
Finally, to calculate the concentration gradient
Answer:
a. the solution will be weakly basic.
b. Greater than 7 because CN⁻ is a stronger base than NH₄⁺ is an acid.
Explanation:
a. The fluoride ion (F⁻) reacts with water thus:
F⁻ + H₂O → HF + OH⁻
That means that fluoride ions produce OH⁻ ions in solution doing <em>the solution will be weakly basic.</em>
b. The acidic equilibrium of NH₄⁺ is:
NH₄⁺ ⇄ NH₃ + H⁺ with a ka of 5,6x10⁻¹⁰.
The basic equilibrium of CN⁻ is:
CN⁻ + H₂O → HCN + OH⁻ with a kb of 2x10⁻⁵
That means that the production of OH⁻ from CN⁻ is higher than production of H⁺ from NH₄⁺. The CN⁻ is a stronger base than NH₄⁺ is an acid.
Thus, the pH of a salt solution of NH₄CN would be <em>Greater than 7 because CN⁻ is a stronger base than NH₄⁺ is an acid.</em>
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I hope ot helps!
