What is the mass/volume percent of a solution with 7.5g of Na2CO3 dissolved in 20.0 g of water?
9.3 %
27%
7.5%

Answer:

The correct answer is 146 g/mol

Explanation:

Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:

ΔTf = Kf x m

Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:

ΔTf = 1.02ºC

Kf = 5.12ºC/m

From this, we can calculate the molality:

m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m

The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:

0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute

There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:

molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol

Therefore, the molar mass of the compound is 146 g/mol

Answer:

In carbon dioxide, on the right, there is 2.666 g of oxygen for every gram of carbon. So the ratio of oxygen in the two compounds is 1:2, a small whole number ratio

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Answer:

The correct option is C

Explanation:

Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.

Answer:

35.1% is percent yield

Explanation:

Full question: Assume no volume change.  If you formed 0.0910 atm of gas, what is the percent yield?

The reaction that is occurring is:

Ni + 3HBr → NiBr₃ + 3/2H₂(g)

First, we will determine moles of Ni and HBr to determine limiting reactant and theoretical yield

Using ideal gas law, we can determine the moles of hydrogen formed. Thus, we can find percent yield:

Moles Ni (Molar mass: 58.69g/mol):

1.02g * (1mol / 58.69g) = 0.01738moles Ni

Moles HBr:

0.750L * (0.112mol/L) = 0.084 moles of HBr.

For a complete reaction of the 0.084 moles of HBr you need:

0.084mol HBr * (1 mole Ni / 3 moles HBr) = 0.028 moles of Ni.

As there are just 0.01738 moles of Ni, the Ni is limiting reactant. Assuming a theoretical yield, moles of H₂ produced are:

0.01738moles Ni * (3/2 H₂ / 1 mol Ni) = 0.02607 moles H₂

Now, moles of H₂ produced are:

PV = nRT

PV/RT = n

Where P is pressure (0.0910atm)

V is volume (2.50L)

R is gas constant (0.082atmL/molK)

T is absolute temperature in Kelvin (30°C + 273.15 = 303.15K)

And n are moles

PV/RT = n

0.0910atm*2.50L/0.082atmL/molK*303.15K = n

0.00915 moles = n

And percent yield (Produced moles / Theoretical moles * 100) is:

0.00915 moles / 0.02607moles =

Answer:

3.48 x 1013 N2 molecules

step-by-step explanation:

Lets set up our equation first

P = 1.00 x 10-6 mm Hg T = 0.0° C + 273 = 273 K

We are given the V = 985 mL ,

R = 0.0821 L·atm/mol·K

Now use the ldeal gas law, but we are solving n, amount of substanvce

PV = nRT, we will change this equation to ;

n = PV/RT

n = 1.00 x 10-6 mm x 1 atm/760 mm x 985 mL x 1 L/103

mL/

(0.0821 L·atm/mol·K x 273 K) = 5.78 x 10-11 moles N2

nmolecules = 5.78 x 10-11 moles N2 x 6.02 x 1023 N2 molecules/1 mol N2

Answer:

1 Faraday

Explanation:

This question seeks to test proper understanding of Faraday's second law of electrolysis which states when the same quantity electricity passes through a solution of different electrolytes, the mass of the substance deposited is directly proportional to there chemical equivalence.

This law hints at the charges of ions being the chemical equivalence and also been represented as the unit for the quantity of electricity in faraday, F. Hence, a metal with the charge of 1+ can be displaced by 1F (which is equal to 96, 500 coloumbs). This charge also represents one molecule of electron, thus 1 faraday corresponds to one mole of electrons.

NOTE: It should be noted that a metal with the charge of 2+ can be displaced by 2F and so on.

Answer:

heat is mesured in calories and also joules

Explanation:

Answer:

Explanation:

Kb of  (CH₃)₃N is 7.4 x 10⁻⁵

initial concentration of (CH₃)₃N   a   is .48 M

(CH₃)₃N    +   H₂O =  (CH₃)₃NH⁺  +  OH⁻

a - x                                     x               x  

x² / (a - x )  = Kb

x is far less than a so a - x can be replaced by a .

x² / a   = Kb

x²  = a x Kb = .48 x 7.4 x 10⁻⁵ = 3.55 x 10⁻⁵ = 35.5 x 10⁻⁶

x = 5.96 x 10⁻³

pOH = - log ( 5.96 x 10⁻³ )

= 3 - log 5.96

= 3 - .775

= 2.225

Answer: it is B

Explanation:

Answer:

Explanation:

The mass of the object can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

where

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{6}{12} = \frac{1}{2} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

The mass of object is 0.5 Kg.

Explanation:

Given data:

Acceleration of object = 12.0 m/s²

Force on object = 6.0 N

Mass of object = ?

Solution:

Formula:

F = m×a

F = force

m = mass

a = acceleration

Now we will put the values in formula.

6.0 N = m  × 12.0 m/s²

m =  6.0 N / 12.0 m/s²  

  ( N = kg.m/s²)

m = 0.5 kg

The mass of object is 0.5 Kg.

Answer: The percent yield of this combination reaction is 41.3 %

Explanation : Given,

Mass of [tex]Na[/tex] = 5.0 g

Mass of [tex]Cl_2[/tex] = 10.0 g

Molar mass of [tex]Na[/tex] = 23 g/mol

Molar mass of [tex]Cl_2[/tex] = 71 g/mol

First we have to calculate the moles of [tex]Na[/tex] and [tex]Cl_2[/tex].

[tex]\text{Moles of }Na=\frac{\text{Given mass }Na}{\text{Molar mass }Na}[/tex]

[tex]\text{Moles of }Na=\frac{5.0g}{23g/mol}=0.217mol[/tex]

and,

[tex]\text{Moles of }Cl_2=\frac{\text{Given mass }Cl_2}{\text{Molar mass }Cl_2}[/tex]

[tex]\text{Moles of }Cl_2=\frac{10.0g}{71g/mol}=0.141mol[/tex]

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation will be:

[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]

From the balanced reaction we conclude that

As, 2 mole of [tex]Na[/tex] react with 1 mole of [tex]Cl_2[/tex]

So, 0.217 moles of [tex]Na[/tex] react with [tex]\frac{0.217}{2}=0.108[/tex] moles of [tex]Cl_2[/tex]

From this we conclude that, [tex]Cl_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]Na[/tex] is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of [tex]NaCl[/tex]

From the reaction, we conclude that

As, 2 mole of [tex]Na[/tex] react to give 2 mole of [tex]NaCl[/tex]

So, 0.217 mole of [tex]HCl[/tex] react to give 0.217 mole of [tex]NaCl[/tex]

Now we have to calculate the mass of [tex]NaCl[/tex]

[tex]\text{ Mass of }NaCl=\text{ Moles of }NaCl\times \text{ Molar mass of }NaCl[/tex]

Molar mass of [tex]NaCl[/tex] = 58.5 g/mole

[tex]\text{ Mass of }NaCl=(0.217moles)\times (58.5g/mole)=12.7g[/tex]

Now we have to calculate the percent yield of this reaction.

Percent yield = [tex]\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100[/tex]

Actual yield = 5.24 g

Theoretical yield = 12.7 g

Percent yield = [tex]\frac{5.24g}{12.7g}\times 100[/tex]

Percent yield = 41.3 %

Therefore, the percent yield of this combination reaction is 41.3 %

Answer:

Explanation:

Here you go!! Hope this helps.

Answer:

48000

Explanation:

maths

Answer:

48000

Explanation:

(5x10^3) = 5 × 1000 = 5000

(4.3x10^4) = 4.3 × 10000 = 43000

5000 + 43000 = 48000

Answer:

The correct answer is b.

Explanation:

hope this helps u

Answer:

Bryna is correct it is B

Explanation:

Answer:

In this example, a 3 kilogram mass, at a height of 5 meters, while acted on by Earth's gravity would have 147.15 Joules of potential energy, PE = 3kg * 9.81 m/s 2 * 5m = 147.15 J. 9.81 meters per second squared (or more accurately 9.80665 m/s 2 ) is widely accepted among scientists as a working average value for Earth's gravitational pull.

Explanation:

Answer:

plucking is usually extracting hair

Explanation:

example: pluck the chicken feathers

pluck my brows

Answer:

It's a representative metal

Explanation: Transitional metals are metals of various chemical elements and have valence electrons—i.e., electrons that can participate in the formation of chemical bonds.

Answer:

You would add its kinetic and potential energies.

Explanation:

Hope this helps!! :)

Answer:

A) Add its kinetic and potential energies

Explanation:

I got it right on Edge 2022

Answer:

0.296j/g⁰c

Explanation:

we have the following information from this question before us.

mass iv substance = 50grams

we have initial temperature ti = 20.2⁰c

final temperature = 125⁰c

the energy that was provided = 155kj

we proceed with this formula

energy = mcΔT

1.55x10³ = 50 x c x (125-20.2)

1.55x10³ = c x 50gm x 104.8k

we divide through to get c

c = 1.55x10³/50g x 104.8

c = 0.296J/g⁰c

that is the specific heat of this substance.

thank you!

Answer:

10 moles of water are produced,

Explanation:

Given data:

Moles of H = 10 mol

Moles of O = 6 mol

Water obtained = ?

Solution:

Balance chemical equation:

2H₂ + O₂    →    2H₂O

Now we will compare the moles of H₂ and O₂ with water from balance chemical equation.

                            H₂             :          H₂O

                             2              :            2

                             10             :           10

                            O₂             :          H₂O

                             1              :            2

                             6             :           2×6 = 12

Number of moles of water produced by hydrogen are less so hydrogen will be limiting reactant and it will limit the yield of water thus, 10 moles of water are produced.

Answer:

geosphere

Explanation:

geo means rocks this is the area

hope this helps dude

Answer:

The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]

Explanation:

We know that 1 ppm is equal to 1 mg/L.

So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.

The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.

So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.

Number of moles = (Mass)/(Molar mass)

Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:

[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]

So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.

Answer:

An element is atoms with the same number of protons.

Explanation:

Protons, electrons, and neutrons.

Answer:

[tex]k=6.48x10^{-3}M^{-1}s^{-1}[/tex]

Explanation:

Hello.

In this case, based on the given information, we can write the rate law as shown below:

[tex]r=k[H_2O_2][KI][/tex]

Since the overall order of reaction is 2 being 1 for reach reactant. Thus, by knowing the initial rate and concentrations, the rate constant turns out:

[tex]k=\frac{r}{[H_2O_2][KI]}=\frac{7.50x10^{-4}M/s}{0.546M*0.212M}\\ \\k=6.48x10^{-3}M^{-1}s^{-1}[/tex]

Best regards!

The rate constant, k is [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]

The rate law should be

[tex]r = k[H_2O_2]{KI}[/tex]

Since the total order of the reaction is 2 being 1 for reach reactant. So, by knowing the beginning rate and concentrations, the rate constant turns out:

[tex]k = \frac{r}{k[H_2O_2]{KI}} = \frac{7.50x10^{-4}M/s}{0.546M\times 0.212M}[/tex]

k = [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]

Learn more about reactants here; https://brainly.com/question/21029530