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3 years ago

Question 1 (1 point)

Chemistry

1 answer:

Zepler [3.9K]3 years ago

4 0

Answer:

density

Explanation:

There are, mainly, three states of matter <em>(solid, liquid and gas). </em>These can be defined differently from the other according to their physical properties. In order to do this, scientists use the word "density" to compare their properties.

Solid has a <em>higher density</em> compared to liquid and gas. This is because its <u>particles are tightly packed.</u> Liquid has a<em> lower density</em> when compared to solid because its particles are loosely arranged. Gas has the <em>lowest density among the three. </em>This means that the <u>gas particles have a very big space,</u> thus rising to a <em>higher kinetic energy. </em>

Thus, this explains the answer.

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Write a balanced chemical equation based on the following description:

kupik [55]

The balanced chemical equation for the reaction is

From the question given above, we were told that:

solid cesium reacts with solid cesium nitrite to form solid cesium oxide and nitrogen gas.

The equation for the reaction can be written as follow:

Caesium => Cs

Caesium nitrite => CsNO₂

cesium oxide => Cs₂O

nitrogen gas => N₂

Caesium + Caesium nitrite —> Caesium oxide + Nitrogen gas

The above equation can be balance as follow:

Cs + CsNO₂ —> Cs₂O + N₂

There are 2 atoms of N on the right side and 1 atom on the left side. It can be balance by writing 2 before CsNO₂ as shown below:

Cs + 2CsNO₂ —> Cs₂O + N₂

There are 2 atoms of Cs on the right side and a total 3 atoms on the left side. It can be balance by writing 6 before Cs and 4 before Cs₂O as shown below:

6Cs(s) + 2CsNO₂(s) —> 4Cs₂O(s) + N₂(g)

Now the equation is balanced

Learn more: brainly.com/question/11502387

5 0

3 years ago

Read 2 more answers

How many milliliters of a 0.40%(w/v) solution of nalorphine must be injected to obtain a dose of 1.5 mg?

ozzi

The number of Ml of a 0.40 %w/v solution of ,nalorphine that must be injected to obtain a dose of 1.5 mg is calculated as below

since M/v% is mass of solute in grams per 100 ml

convert Mg to g
1 g = 1000 mg what about 1.5 mg =? grams
= 1.5 /1000 = 0.0015 grams

volume is therefore = 100 ( mass/ M/v%)

= 100 x( 0.0015/ 0.4) = 0.375 ML

6 0

4 years ago

A solution was prepared by dissolving 195.0 g of KCl in 215 g of water. Calculate the mole fraction of KCl. (The formula weight

defon

Answer:

Approximately $0.180$ .

Explanation:

The mole fraction of a compound in a solution is:

$\displaystyle \frac{\text{Number of moles of compound in question}}{\text{Number of moles of all particles in the solution}}$ .

In this question, the mole fraction of $\rm KCl$ in this solution would be:

$\displaystyle X_\mathrm{KCl} = \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}$ .

This solution consist of only $\rm KCl$ and water (i.e., $\rm H_2O$ .) Hence:

$\begin{aligned} X_\mathrm{KCl} &= \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}\\ &= \frac{n(\mathrm{KCl})}{n(\mathrm{KCl}) + n(\mathrm{H_2O})}\end{aligned}$ .

From the question:

Mass of $\rm KCl$ : $m(\mathrm{KCl}) = 195.0\; \rm g$ .
Molar mass of $\rm KCl$ : $M(\mathrm{KCl}) = 74.6\; \rm g \cdot mol^{-1}$ .

Mass of $\rm H_2O$ : $m(\mathrm{H_2O}) = 215\; \rm g$ .
Molar mass of $\rm H_2O$ : $M(\mathrm{H_2O}) = 18.0\; \rm g\cdot mol^{-1}$ .

Apply the formula $\displaystyle n = \frac{m}{M}$ to find the number of moles of $\rm KCl$ and $\rm H_2O$ in this solution.

$\begin{aligned}n(\mathrm{KCl}) &= \frac{m(\mathrm{KCl})}{M(\mathrm{KCl})} \\ &= \frac{195.0\; \rm g}{74.6\; \rm g \cdot mol^{-1}} \approx 2.61\; \em \rm mol\end{aligned}$ .

$\begin{aligned}n(\mathrm{H_2O}) &= \frac{m(\mathrm{H_2O})}{M(\mathrm{H_2O})} \\ &= \frac{215\; \rm g}{18.0\; \rm g \cdot mol^{-1}} \approx 11.9\; \em \rm mol\end{aligned}$ .

The molar fraction of $\rm KCl$ in this solution would be:

$\begin{aligned} X_\mathrm{KCl} &= \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}\\ &= \frac{n(\mathrm{KCl})}{n(\mathrm{KCl}) + n(\mathrm{H_2O})} \\ &\approx \frac{2.61 \; \rm mol}{2.61\; \rm mol + 11.9\; \rm mol} \approx 0.180\end{aligned}$ .

(Rounded to three significant figures.)

8 0

3 years ago

Elements donate 2 electron to produce a cation with a 2+ charge

hammer [34]

Answer: alkaline earth metals (group-IIA)

Explanation:

The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.

Alkaline earth metals donate 2 valence electrons to acquire noble gas configuration.

For example: Berrylium is the first alkaline earth metal with atomic number of 4 and thus has 4 electrons

Electronic configuration of berrylium:

$[Be]:4:1s^22s^2$

Berrylium atom will loose two electrons to gain noble gas configuration and form berrylium cation with +2 charge.

$[Be^{2+}]:2:1s^2$

Thus Elements donate 2 electron to produce a cation with a 2+ charge are alkaline earth metals.

5 0

3 years ago

Give the SI base unit of each of these quantities. Enter the abbreviation rather than the name of the unit. mass: __________--le

Vladimir [108]

Answer: mass : kg, length: meter, time: second, temperature: Kelvin

Explanation:

Mass is defined as the amount of matter contained in the body.

Its units are kg, gram, milligram which are inter convertible.

S.I or M.K.S system has seven fundamental units which are used to find derived units

1) Mass - Kilogram

2) Length - meter

3) Time - Seconds

4) Electric Current - Ampere

5) Amount of substance - Moles

6) Intensity of light - Candela

7) Temperature - Kelvin

Thus SI base unit of each of these quantities are kg, meter, second, and Kelvin

4 0

4 years ago