Is chlorine a substance or a mixture

A solution is made by dissolving 4.87 g of potassium nitrate in water to a final volume of 86.4 mL solution. What is the weight/

lara31 [8.8K]

Answer:

A solution is made by dissolving 4.87 g of potassium nitrate in water to a final volume of 86.4 mL solution. The weight/weight % or percent by mass of the solute is :

2.67%

Explanation:

Note : Look at the density of potassium nitrate in water if given in the question.

You are calculating weight /Volume not weight/weight % or percent by mass of the solute

Here the weight/weight % or percent by mass of the solute is asked : So first convert the VOLUME OF SOLUTION into MASS

Density of potassium nitrate in water KNO3 = 2.11 g/mL

$density=\frac{mass}{volume}$

Density = 2.11 g/mL

Volume of solution = 86.4 mL

$2.11=\frac{mass}{86.4}$

$mass = 2.11\times 86.4$

$mass=182.3grams$

Mass of Solute = 4.87 g

Mass of Solution = 183.2 g

w/w% of the solute =

$= \frac{mass\ of\ solute}{mass\ of\ solution}\times 100$

$=\frac{4.87}{183.2}\times 100$

w/w%=2.67%

8 0

3 years ago

How is stoichiometry used to calculate the amount of product from amount of reactant?

IceJOKER [234]

Stoichiometry deals with the quantitative measurement of reactants and products in a chemical reaction. Let suppose you are given with following reaction;

A + 2 B → 3 C

According to this reaction 1 mole of A reacts with 2 moles of B to produce 3 moles of C. Now using the concept of mole one can easily measure the amount of reactants reacted and the amount of product formed, as...

1 Mole Exactly equals 6.022 × 10²³ particles

1 Mole of Gas (at STP) exactly occupies 22.4 L Volume

1 Mole of any compound exactly equals the molar mass in grams

Therefore, Stoichiometry is very helpful in quantitative analysis.

6 0

3 years ago

Read 2 more answers

A flash contains 85.6g of C7H5NO3S (Saccharine) in 2.00 litre of a solution. What is the molarity?

larisa86 [58]

Answer:

0.234 M

Explanation:

C- 12.009 x 7

H- 1.001 x 5

N- 14.006

O- 16 x 3

S- 32.059

___________+

183.133 g/mol

$\frac{1mol}{183.133g} *\frac{85.6g}{2.00L}$ = 0.234 M Cancel out the grams mol/L equals molarity. Lowest significant figure is 3

7 0

3 years ago

A 3.31-g sample of lead nitrate, Pb(NO3)2, molar mass = 331 g/mol, is heated in an evacuated cylinder with a volume of 2.53 L. T

Dahasolnce [82]

Answer:

0.486atm is the pressure of the cylinder

Explanation:

1 mole of Pb(NO₃)₂ descomposes in 4 moles of NO2 and 1 mole of O2. That is 1 mole descomposes in 5 moles of gas.

To find the pressure of the cylinder, we need to find moles of gas produced, and using general gas law we can determine the pressure of the gas:

Moles Pb(NO₃)₂ and moles of gas:

3.31g * (1mol / 331g) = 0.01 moles of Pb(NO₃)₂.

That means moles of gas produced is 0.05 moles.

Pressure of the gas:

Using PV = nRT

P = nRT/V

Where P is pressure (Incognite)

V is volume (2.53L)

R is gas constant (0.082atmL/molK)

T is absolute temperature (300K)

And n are moles of gas (0.05 moles)

P = 0.05mol*0.082atmL/molK*300K / 2.53L

P = 0.486atm is the pressure of the cylinder

3 0

3 years ago

What is heating and cooling

melisa1 [442]

make or become hot or warm is heating.

cooling is to become colder or cool down from a higher temp.

6 0

4 years ago