All categories

2 years ago

Which element can form a chloride with a general formula of MCl2 or MCl3

1 answer:

5 0

Oxidation state number can be used to determine the unknown element in these two compounds. They are used to determine how many electrons are given, taken or shared to form compounds.

Recall the elementary rules of oxidation numbers.

1. The sum of all oxidation numbers in a neutral compound is zero.
2. Chlorine, bromine, iodine have oxidation number of -1 ( except compounds with fluorine and oxygen)

Let oxidation number of element M be x.
Check rule 2. Chlorine has -1 oxidation number.

Now we write an equation of MCl₂ (neutral compound)
x + (2 * -1)= 0 ⇒ x₁= +2

For MCl₃
x + (3 * -1)= 0 ⇒ x₂= +3

So element has 2 different oxidation number in compounds, +2 and +3.

The element is iron (Fe) since it has +2 and +3 oxidation numbers in the compounds.

You need to learn it by hard. Unfortunately there is not an easier way to work out with these oxidation numbers.

The answer is iron (Fe).

You might be interested in

What do you do with unused (excess) chemicals that are taken from reagent bottles?

Tanzania [10]

Don't ever return unused chemicals to their original containers. If you do, you could be contaminating the chemical. Discard the leftover chemical in the correct waste box. Ask your teacher if your not sure about what to do.

4 0

2 years ago

Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic

Kisachek [45]

Answer:

A) 10.75 is the concentration of arsenic in the sample in parts per billion .

B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C) It will take 1.37 years to remove all of the arsenic from the lake.

Explanation:

A) Mass of arsenic in lake water sample = 164.5 ng

The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.

To calculate the ppm of oxygen in sea water, we use the equation:

$\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9$

Both the masses are in grams.

We are given:

Mass of arsenic = 164.5 ng = $164.5\times 10^{-9} g$

$1 ng=10^{-9} g$

Volume of the sample = V = $15.3 cm^3$

Density of the lake water sample ,d= $1.00 g/cm^3$

Mass of sample = M = $d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g$

$ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75$

10.75 is the concentration of arsenic in the sample in parts per billion.

Mass of arsenic in $1 cm^3$ of lake water = $\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g$

Mass of arsenic in $0.710 km^3$ lake water be m.

$1 km^3=10^{15} cm^3$

Mass of arsenic in $0.710\times 10^{15} cm^3$ lake water :

$m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g$

1 g = 0.001 kg

7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg

7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

$\frac{2.74}{41.90} days$

Then days required to remove 7,633.66 kg of arsenic from the lake water :

$=7,633.66\times \frac{2.74}{41.90} days=499.19 days$

1 year = 365 days

499.19 days = $\frac{499.19}{365} years = 1.367 years\approx 1.37 years$

It will take 1.37 years to remove all of the arsenic from the lake.

3 0

2 years ago

Which of the following actions cannot induce voltage in a wire?

MariettaO [177]

Your answer is D. Since there is little to no magnetic field to wire, if it is copper which most wires are, there will be no voltage in a wire.

7 0

2 years ago

Read 2 more answers

In the first paragraph, the words "disrobed," "unveiling" and "deconstructed" primarily serve to

Solnce55 [7]

Complete Question:

In the first paragraph, the words “disrobed,” “unveiling” and “deconstructed” primarily serve to (a) highlight the negative connotations that laser technology currently has, (b) emphasize the extensive reach of laser technology; (c) demonstrate the inherently unknowable characteristics of objects, even with laser technology; (d) implicitly compare lasers to other forms of technology

Answer:

(b) emphasize the extensive reach of laser technology;

Explanation:

The use of the word disrobed and deconstructed from the passage emphasizes the extensive reach of laser technology. Even without looking up the dictionary meaning of the two words, one can easily deduce that the passage is a pro-laser technology one.

The passage presents the use of the laser technology in solar exploration.
It also show its use by ecologists.

#learnwithBrainly

8 0

2 years ago

Read 2 more answers

Calculate the pka of hypochlorous acid. The ph of a 0.015 m solution of hypochlorous acid has a ph of 4.64.

o-na [289]

Answer:

pKa = 7.46

Explanation:

1) Data:

a) Hypochlorous acid = HClO

b) [HClO} = 0.015

c) pH = 4.64

d) pKa = ?

2) Strategy:

With the pH calculate [H₃O⁺], then use the equilibrium equation to calculate the equilibrium constant, Ka, and finally calculate pKa from the definition.

3) Solution:

a) pH

pH = - log [H₃O⁺]

4.64 = - log [H₃O⁺]

$[H_3O^+]= 10^{-4.64} = 2.29.10^{-5}$

b) Equilibrium equation: HClO (aq) ⇄ ClO⁻ (aq) + H₃O⁺ (aq)

c) Equilibrium constant: Ka = [ClO⁻] [H₃O⁺] / [HClO]

d) From the stoichiometry: [CLO⁻] = [H₃O⁺] = 2.29 × 10 ⁻⁵ M

e) By substitution: Ka = (2.29 × 10 ⁻⁵ M)² / 0.015M = 3.50 × 10⁻⁸ M

f) By definition: pKa = - log Ka = - log (3.50 × 10 ⁻⁸) = 7.46

5 0

2 years ago