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1 year ago

Why is mining for coal a long-term concern?

Chemistry

2 answers:

Free_Kalibri [48]1 year ago

8 0

A. Fossil fuels take a very long time to form so we mine it faster than it can replenish.

maw [93]1 year ago

5 0

Answer: I believe its A

Explanation:

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2 attempts left select the single best answer. The radii of the lithium and magnesium ions are 76 pm and 72 pm, respectively. Wh

Lina20 [59]

The ionic character of any compound depend on the lattice energy as well as the electronegativity of element present in that compound.

More would be the lattice energy more would be ionic nature of that compound.

The lattice energy of any compound is inversely proportional to the ionic radii cation and anion.

In given case the ionic radii of oxide in both oxides would be equal therefore the lattice energy only depend on the ionic radii of cation.

$Lattice energy (U) = \frac{1}{Ionic radii}$

As the radii of Magnesium less then radii of lithium therefore lattice energy of Magnesium oxide would be more than lithium oxide.

Hence, MgO would be more ionic in nature than $Li_{2}O$

8 0

2 years ago

The chemical formula for cesium oxide is Cs2O. What is the charge of cesium? +1 +2 –1 –2

aalyn [17]

The Charge Of Cesium Is +1

5 0

2 years ago

Read 2 more answers

When 9.2 g of frozen N2O4 is added to a 0.50 L reaction vessel and the vessel is heated to 400 K and allowed to come to equilibr

Amanda [17]

Answer: The value of $K_c$ for the given reaction is 1.435

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}$

Given mass of $N_2O_4$ = 9.2 g

Molar mass of $N_2O_4$ = 92 g/mol

Volume of solution = 0.50 L

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{9.2g}{92g/mol\times 0.50L}\\\\\text{Molarity of solution}=0.20M$

For the given chemical equation:

$N_2O_4(g)\rightleftharpoons 2NO_2(g)$

Initial: 0.20

At eqllm: 0.20-x 2x

We are given:

Equilibrium concentration of $N_2O_4$ = 0.057

Evaluating the value of 'x'

$\Rightarrow (0.20-x)=0.057\\\\\Rightarrow x=0.143$

The expression of $K_c$ for above equation follows:

$K_c=\frac{[NO_2]^2}{[N_2O_4]}$

$[NO_2]_{eq}=2x=(2\times 0.143)=0.286M$

$[N_2O_4]_{eq}=0.057M$

Putting values in above expression, we get:

$K_c=\frac{(0.286)^2}{0.143}\\\\K_c=1.435$

Hence, the value of $K_c$ for the given reaction is 1.435

6 0

2 years ago

When 100 ml of 1.0 M Na3PO4 is mixed with 100 ml of 1.0 M AgNO3,a yellow precipitate forms and Ag+ becomes negligibly small. Whi

jok3333 [9.3K]

Answer:

Option A

Explanation:

Number of millimoles of Na3PO4 = 1 × 100 = 100

Number of millimoles of AgNO3 = 1 × 100 = 100

When 1 mole of Na3PO4 is dissociated we get 3 moles of sodium ions and 1 mole of phosphate ion

When 1 mole of AgNO3 is dissociated, we get 1 mole of Ag+ and 1 mole of NO3-

As Ag+ concentration is negligible, the dissociated Ag+ ion must have form the precipitate with phosphate ion and as number of moles of Ag+ and phosphate ion are same, therefore the concentration of phosphate ion must be negligible

Here as 100 millimoles of Na3PO4 is there, we get 300 millimoles of Na+ and 100 millimoles of PO43-

And as 100 millimoles of AgNO3 is there, we get 100 millimoles of Ag+ and 100 millimoles of NO3-

∴ Increasing order of concentration will be PO43- < NO3- < Na+

4 0

2 years ago

Read 2 more answers

What is the empirical formula of a compound containing 5.03 grams carbon, 0.42 grams hydrogen, and 44.5 grams chlorine?

Thepotemich [5.8K]

Answer:

CHCl₃

Explanation:

Given parameters:

Carbon = 5.03g

Hydrogen = 0.42g

Chlorine = 44.5g

The empirical formula shows the simplest formula of a compound.

To deduce the empirical, we need two pieces of information:

> Mass of the elements or the percentage composition of the compound

>The relative atomic masses of the elements

In order to derive the empirical formula from these parameters,

>>> find the number of moles of elements by dividing the mass given by the relative atomic mass of the respective atom

>>> Divide through by the smallest mole

>>> Approximate or multiply by a factor that would make it possible for whole numbers to be obtained

From the question, we have been given the mass of each element.

Now using the period table, we can obtain the relative atomic masses of each atom:

Carbon = 12gmol⁻¹

Hydrogen = 1gmol⁻¹

Chlorine = 37.5gmol⁻¹

C H Cl

Mass(in g) 5.03 0.42 44.5

Moles 5.03/12 0.42/1 44.5/37.5

0.42 0.42 1.19

Dividing

smallest 0.42/0.42 0.42/0.42 1.19/0.42

Mole ratio 1 1 2.83

Approximate 1 1 3

The empirical formula is CHCl₃

8 0

2 years ago