Which is one feature of the ocean floor found in the open ocean?

A 5.000 g mixture contains strontium nitrate and potassium bromide. Excess lead(II) nitrate solution is added to precipitate out

scZoUnD [109]

<u>Answer:</u> The mass percent of potassium bromide in the mixture is 9.996%

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

<u>For lead (II) bromide:</u>

Given mass of lead (II) bromide = 0.7822 g

Molar mass of lead (II) bromide = 367 g/mol

Putting values in equation 1, we get:

$\text{Moles of lead (II) bromide}=\frac{0.7822g}{367g/mol}=0.0021mol$

The chemical equation for the reaction of lead (II) nitrate and potassium bromide follows:

$2KBr+Pb(NO_3)_2\rightarrow PbBr_2+2KNO_3$

By Stoichiometry of the reaction:

1 mole of lead (II) bromide is produced from 2 moles of potassium bromide

So, 0.0021 moles of lead (II) bromide will be produced from = $\frac{2}{1}\times 0.0021=0.0042mol$ of potassium bromide

Now, calculating the mass of potassium bromide by using equation 1, we get:

Molar mass of KBr = 119 g/mol

Moles of KBr = 0.0042 moles

Putting values in equation 1, we get:

$0.0042mol=\frac{\text{Mass of KBr}}{119g/mol}\\\\\text{Mass of KBr}=0.4998g$

To calculate the percentage composition of KBr in the mixture, we use the equation:

$\%\text{ composition of KBr}=\frac{\text{Mass of KBr}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 5.000 g

Mass of KBr = 0.4998 g

Putting values in above equation, we get:

$\%\text{ composition of KBr}=\frac{0.4998g}{5.000g}\times 100=9.996\%$

Hence, the percent by mass of KBr in the mixture is 9.996 %

5 0

3 years ago

Acetone (nail polish remover) has a density of 0.7857 g >cm3.

Stella [2.4K]

If acetone has a density of 0.7857 $\frac{g}{cm^{3} }$ the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.

<h3>What is acetone?</h3>

Acetone is known as a chemical substance that is usually found in the environment but can also be produced artificially. Acetone is a polar organic product that interacts very well with water molecules, generating dipole-dipole relationships.It is colorless with a distinctive smell and taste, we find it in products known as <u>cleaning and personal care products</u>, but we can also use it as a solvent for substances.

Also in the environment in <u>plants, trees and in volcano emissions or in forest fires</u>, it does not become <em>toxic</em> in low doses but if it is exposed to an individual in high doses it can become <em>fatal</em>.

In the statement we can find that acetone has a density of 0.7857 $\frac{g}{cm^{3} }$ .

Therefore, we can confirm that if acetone has a density of 0.7857 $\frac{g}{cm^{3} }$ the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.

To learn more about acetone visit: brainly.com/question/13334667?referrer=searchResults

#SPJ1

7 0

2 years ago

Calcium carbide, CaC2, is manufactured by reducing lime with carbon at high temperature. (The carbide is used in turn to make ac

sweet-ann [11.9K]

The energy of the carbide released is 7262.5MJ.

<h3>What is the energy?</h3>

We know that the reaction between calcium oxide and carbon occurs in accordance with the reaction; $CaO(s)+3C(s)----- > CaC_{2} (s)+CO(g)$ . The reaction is seen to produce 464.8kJ of energy per mole of carbide produced.

Number of moles of $CaC_{2}$ produced = 1000 * 10^3 g/64 g/mol

= 15625 moles of calcium carbide

If 1 mole of $CaC_{2}$ transfers 464.8 * 10^3 J

15625 moles of calcium carbide transfers 15625 moles * 464.8 * 10^3 J/ 1 mol

= 7262.5MJ

Learn more about reaction enthalpy:brainly.com/question/1657608

#SPJ1

7 0

1 year ago

Consider this chemical reaction. What chemical is reduced?<br> CH3OH + NAD --> CH2O + NADH

nikklg [1K]

Answer:

CH3OH and NADH

Explanation:

The given chemical reaction is an redox reaction in which reduction and oxidation take place.

In the process of oxidation: electrons are loss while in the process of reduction: electrons are gained.

In the given redox reaction: CH3OH + NAD --> CH2O + NADH

NAD is reduced to NADH as NADH gains one hydrogen electron while CH3OH (methanol) is oxidized to CH2O (methanal) by losing electrons.

So, CH3OH (methanol) and NADH are the reduced forms while NAD and CH2O (methanal) are oxidized forms.

5 0

3 years ago

Are mass and *weight of matter* the same thing

Scorpion4ik [409]

Answer:

Mass is the quantity of an object.

Weight is the force with which the object is attached towards the earth.

Hope it helps

7 0

3 years ago

Read 2 more answers