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2 years ago

Which of the following types of coal has the highest energy content and produces the fewest polluting chemicals?

Chemistry

1 answer:

4vir4ik [10]2 years ago

4 0

Answer:

Anthracite: The highest rank of coal. This coal is hard, brittle, and black lustrous. It is often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.

Explanation: There are four ranks of coal

Coal rank measures the carbon content which is in correlation with calorific value and metamorphic grade. It has a very high carbon (over 90%) and low volatile content (below 5%)1.

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The ksp of copper(ii) carbonate, cuco3, is 1.4 × 10-10. calculate the molar solubility of this compound.

mafiozo [28]

As,
CuCO₃   ⇆ Cu²⁺ + CO₃²⁻
So,
Kc = [Cu²⁺] [CO₃²⁻] / CuCO₃
Or,
Kc (CuCO₃) = [Cu²⁺] [CO₃²⁻]
Or,
Ksp = [Cu²⁺] [CO₃²⁻]
As,
Ksp = 1.4 × 10⁻¹⁰
So,
1.4 × 10⁻¹⁰ = [x] [x]
Or,
x² =  1.4 × 10⁻¹⁰
Or,
x = 1.18 × 10⁻⁵ mol/L
To cahnge ito g/L,
x =  1.18 × 10⁻⁵ mol/L × 123.526 g/mol

x = 1.45 × 10⁻³ g/L

3 0

2 years ago

A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heatin

vova2212 [387]

Answer: Yes we agree with the student's claim.

Explanation:

When the molecules are present in smaller size, more reactants can react as decreasing the size increases the surface area of the reactants which will enhance the contact of molecules.Hence, more products will form leading to increased rate of reaction.

On increasing the temperature will make more reactant molecules will have sufficient energies to cross the energy barrier and thus the number of effective collisions increases, thus leading to more products and increased rate of reaction.

When the solution is stirred , the molecule's kinetic energy and thus the rate of reaction increases.

Thus smaller size, stirring and increase of temperature will make the solution quickly.

7 0

3 years ago

A student dissolved 1.805g of a monoacidic weak base in 55mL of water. Calculate the equilibrium pH for the weak monoacidic base

yawa3891 [41]

Answer:

11.39

Explanation:

Given that:

$pK_{b}=4.82$

$K_{b}=10^{-4.82}=1.5136\times 10^{-5}$

Given that:

Mass = 1.805 g

Molar mass = 82.0343 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{1.805\ g}{82.0343\ g/mol}$

$Moles= 0.022\ moles$

Given Volume = 55 mL = 0.055 L ( 1 mL = 0.001 L)

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

$Molarity=\frac{0.022}{0.055}$

Concentration = 0.4 M

Consider the ICE take for the dissociation of the base as:

B + H₂O ⇄ BH⁺ + OH⁻

At t=0 0.4 - -

At t =equilibrium (0.4-x) x x

The expression for dissociation constant is:

$K_{b}=\frac {\left [ BH^{+} \right ]\left [ {OH}^- \right ]}{[B]}$

$1.5136\times 10^{-5}=\frac {x^2}{0.4-x}$

x is very small, so (0.4 - x) ≅ 0.4

Solving for x, we get:

x = 2.4606×10⁻³ M

pOH = -log[OH⁻] = -log(2.4606×10⁻³) = 2.61

5 0

2 years ago

A student shines a flashlight on a mirror.

irga5000 [103]

Answer:

Explanation:

mirrors reflect light

7 0

2 years ago

Read 2 more answers

Describe where a hydrogen bond can form among water molecules.

stiv31 [10]

Answer:

In water hydrogen bonding formed between partially negative oxygen and partially positive hydrogen atoms.

Explanation:

Hydrogen bond is a partially electrostatic attraction between hydrogen (H), which is bonded to a more electronegative atom such as nitrogen (N), oxygen (O) or fluorine (F), and another adjacent atom bearing a lone pair of electrons.

In water molecule hydrogen and oxygen have difference in electronegativity, due to which dipoles are form. One is partial positive on hydrogen atom and other is partial negative on oxygen atom. The electrostatic attraction occur between two oppositely charged poles which is known as hydrogen bonding.

4 0

2 years ago