Please help both these answers use the graph . I will mark brainly !!

What is the mole fraction of NaOH in an aqueous solution that

astraxan [27]

Answer:

The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882

Explanation:

We are given that

Aqueous solution that contains 22.9% NaOH by mass means

22.9 g NaOH in 100 g solution.

Mass of NaOH(WB)=22.9 g

Mass of water =100-22.9=77.1

Na=23

O=16

H=1.01

Molar mass of NaOH(MB)=23+16+1.01=40.01

Number of moles = $\frac{Given\;mass}{Molar\;mass}$

Using the formula

Number of moles of NaOH $(n_B)=\frac{W_B}{M_B}=\frac{22.9}{40.01}$

$n_B=0.572moles$

Molar mass of water=16+2(1.01)=18.02g

Number of moles of water $(n_A)=\frac{77.1}{18.02}$

$n_A=4.279 moles$

Now, mole fraction of NaOH

= $\frac{n_B}{n_B+n_A}$

$=\frac{4.279}{0.572+4.279}$

=0.882

Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882

4 0

3 years ago

For the following reaction, identify the element that was oxidized, the element that was reduced, and the reducing agent. Give a

Volgvan

For this reaction, oxidation number of Carbon in CO would be +2 while oxidation number of carbon in CO2 would be +4 and so this means that carbon has oxidized. Oxidation number of nitrogen in NO is +2. While oxidation number of nitrogen in N2 is 0 so this means that nitrogen had reduced. The reducing agent is the one which provides electrons by oxidizing itself so in this case; CO is the reducing agent while the C in CO oxidized to produce electrons. I am hoping that this answer has satisfied your query about and it will be able to help you, and if you’d like, feel free to ask another question.

6 0

3 years ago

The freezing point of a nonelectrolyte solution containing 30.0 g of a solute dissolved in 250.0 g of water is observed to be -2

scZoUnD [109]

Answer:

Molar mass of solute is 89.28 g/m

Explanation:

Colligative property of freezing point depression to solve this:

ΔT = Kf . m . i

i = number of particles, dissolved in solution. In this case, it is a nonelectrolyte, so i = 1.

m = molalilty (mol of solute/1kg of solvent

ΔT = T° freeze pure solvent - T° freeze solution

0°C - (-2.50°C) = 1.86 °C/m . m

2.50°C / 1.86 m/°C = m

1.34 mol solute/kg solvent = m

This means, that in 1000 g of solvent, we have 1.34 moles but we have 250 g of solvent, so let's make a rule of three.

1000 g ____ 1.34 moles

250 g _____(2.50 . 1.34) / 1000 = 0.336 moles

To find the molar mass, we divide mass / moles

30 g/ 0.336 moles = 89.28 g/m

7 0

3 years ago

Borax (na2b4o7Â·10h2o; fw = 381.372 g/mol; density = 1.73 g/ml), a primary standard, was used to standardize a solution of hno3.

SashulF [63]

0.06355391 mol The balanced equation for the reaction is Na2B4O7*10H2O + 2 HNO3 = 2 NaNO3 + 4 H3BO3 + 5 H2O So for each mole of Borax to neutralize, it takes 2 moles of HNO3. Calculate number of moles of Borax 0.2619 g / 381.372 g/mol = 0.0006867 mol Moles of HNO3 used = 0.0006867 mol * 2 = 0.0013734 mol Molarity is defined as moles per liter so divide the number of moles used by the volume in liters. So 0.0013734 / 0.02161 = 0.06355391 mol

3 0

3 years ago

If the reactants contain one chlorine molecule, do you know how many chlorine atoms will be in the product? Include conversion o

max2010maxim [7]

Answer:

The number of Chlorine atoms in the product is 2.

Explanation:

The law of conservation of mass states that matter can neither be created nor destroyed in a chemical reaction.

The reactants contain one chlorine molecule( $Cl_{2}$ ) which has two chlorine atoms.

Then, according to law of conservation of matter, the product must contain two chlorine atoms.

4 0

3 years ago