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3 years ago

Sodium metal is quiet soft whereas sodium chloride crystals are quiet hard explain why

1 answer:

8 0

In mineralogy and crystallography, a crystal structureis a unique arrangement of atoms in a crystal. Acrystal structure is composed of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice.
Crystals create a harder more fitting structure so they tend to be a lot stronger than other compounds or elements

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Cyclohexane (C6H12) is a hydrocarbon (a substance containing only carbon and hydrogen) liquid. Which of the following will most

SVETLANKA909090 [29]

Answer: $CH_{3}CH_{2}CH_{2}CH_{2}CH_{3}$

Explanation: Hydrocarbons are the compounds which contain only carbon and hydrogen as their constituent elements. These are considered to be as the non polar species as because of the less electronegativity difference between the two components.

Now as it is a non polar species thus it will dissolve only a non polar solute following the principle of 'Like dissolves Like'. Thus the most non polar species given in the options is pentane. Cyclohexane will definitely dissolve this pentane as both are non polar in nature.

$CH_{2}Cl_{2}$ , HI and NaBr are polar specie which cannot be dissolved in non polar species.

3 0

3 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

ale4655 [162]

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

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.

6 0

3 years ago

Uranium-236 is _____. created by fusion reactions an unstable isotope of uranium created from four hydrogen atoms used in the H-

nata0808 [166]

Uranium-236 is intermediate nuclei. created by fusion reactions an unstable isotope of uranium created from four hydrogen atoms used in the H-bomb.

Following is the reaction involved in above process:

 $^{235}U$ + $^{1}n$ → $^{236}U$ → $^{144}Ba$ + $^{89}Kr$ + 3 $^{1}n$ + 177 MeV

Here,
$^{235}U$ = Fission material,
$^{1}n$ = projectile,
$^{236}U$ = intermediate nuclei,
$^{144}Ba$ and $^{89}Kr$ = Fission product

8 0

3 years ago

Read 2 more answers

What is the formula mass of (NH4)2SO4

Jobisdone [24]

Answer:

132.17 amu.

Explanation:

6 0

3 years ago

How does the flow of energy during freezing compare with the flow of energy during melting

lianna [129]

Answer:

At the melting point, some molecules overcome the forces of attraction. Energy gained after the the solid melts increases the average kinetic energy or the temperature. When liquid is freezing the energy flows out the the liquid. As the kinetic energy decreases, they move more slowly.

Explanation:

3 0

3 years ago