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3 years ago

Calculate the pOH for a solutions with a pH of 12.34. Is the solution acidic or basic?

Chemistry

1 answer:

alexgriva [62]3 years ago

4 0

Answer:

1.66 basic

Explanation:

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Sodium sulfide reacts with hydrochloric acid to produce hydrosulfuric acid and sodium chloride. (you need to write and balance t

VikaD [51]

Answer:

2.5 moles of NaCl

Explanation:

The balanced chemical reaction equation is shown in the image. Since it takes 2 moles of Hydrochloric acid to form two moles of sodium. Chloride, then 2.5 moles of hydrochloric acid should also form 2.5 moles of sodium chloride according to the balanced reaction equation.

4 0

3 years ago

Pablo's experiments confirm the relationship between pressure and the number of gas molecules. as the pressure in a system incre

horrorfan [7]

The correct answer is: [C]:
___________________________________________________________
"pressure and the number of gas molecules are directly related."
___________________________________________________________
Note: The conclusion was: " as the pressure in a system increases, the number of gas molecules increases" — over the course of many trials.
This means that the "pressure" and the "number of gas molecules" are directly related.

Furthermore, this conclusion is consistent with the "ideal gas law" equation:

" PV = nRT " ;
____________________________________________________________
in which:

"P = Pressure" ;
"n = number of gas molecules" ;
___________________________________________________________
All other factors held equal, when "n" (the "number of gas molecules")
increases in value (on the "right-hand side" of the equation), the value for "P" (the "pressure" — on the "left-hand side" of the equation), increases.
___________________________________________________________

6 0

3 years ago

Read 2 more answers

A compound is 42.9% C, 2.4% H, 16.7% N, and 38.1% O, by mass. Addition of 6.45 g of this compound to 50.0 mL benzene, lowers the

Romashka [77]

This is an incomplete question, here is a complete question.

A compound is 42.9% C, 2.4% H, 16.7% N and 38.1% O by mass. Addition of 6.45 g of this compound to 50.0 mL benzene, C₆H₆ (d= 0.879 g/mL; Kf= 5.12 degrees Celsius/m), lowers the freezing point from 5.53 to 1.37 degrees Celsius. What is the molecular formula of this compound?

Answer : The molecular of the compound is, $C_6H_4N_2O_4$

Explanation :

First we have to calculate the mass of benzene.

$\text{Mass of benzene}=\text{Density of benzene}\times \text{Volume of benzene}$

$\text{Mass of benzene}=0.879g/mL\times 50.0mL=43.95g$

Now we have to calculate the molar mass of unknown compound.

Given:

Mass of unknown compound (solute) = 6.45 g

Mass of benzene (solvent) = 43.95 g = 0.04395 kg

Formula used :

$\Delta T_f=K_f\times m\\\\\Delta T_f=K_f\times\frac{\text{Mass of unknown compound}}{\text{Molar mass of unknown compound}\times \text{Mass of benzene in Kg}}$

where,

$\Delta T_f$ = change in freezing point = $5.53-1.37=4.16^oC$

$\Delta T_s$ = freezing point of solution

$\Delta T^o$ = freezing point of benzene

Molal-freezing-point-depression constant $(K_f)$ for benzene = $5.12^oC/m$

m = molality

Now put all the given values in this formula, we get

$4.16^oC=(5.12^oC/m)\times \frac{6.45g}{\text{Molar mass of unknown compound}\times 0.04395kg}$

$\text{Molar mass of unknown compound}=180.6g/mol$

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of C = 42.9 g

Mass of H = 2.4 g

Mass of N = 16.7 g

Mass of O = 38.1 g

Molar mass of C = 12 g/mole

Molar mass of H = 1 g/mole

Molar mass of N = 14 g/mole

Molar mass of O = 16 g/mole

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{42.9g}{12g/mole}=3.575moles$

Moles of H = $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{2.4g}{1g/mole}=2.4moles$

Moles of N = $\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{16.7g}{14g/mole}=1.193moles$

Moles of O = $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{38.1g}{16g/mole}=2.381moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{3.575}{1.193}=2.99\approx 3$

For H = $\frac{2.4}{1.193}=2.01\approx 2$

For N = $\frac{1.193}{1.193}=1$

For O = $\frac{2.381}{1.193}=1.99\approx 2$

The ratio of C : H : N : O = 3 : 2 : 1 : 2

The mole ratio of the element is represented by subscripts in empirical formula.

The Empirical formula = $C_3H_2N_1O_2$

The empirical formula weight = 3(12) + 2(1) + 1(14) + 2(16) = 84 gram/eq

Now we have to calculate the molecular formula of the compound.

Formula used :

$n=\frac{\text{Molecular formula}}{\text{Empirical formula weight}}$

$n=\frac{180.6}{84}=2$

Molecular formula = $(C_3H_2N_1O_2)_n=(C_3H_2N_1O_2)_2=C_6H_4N_2O_4$

Therefore, the molecular of the compound is, $C_6H_4N_2O_4$

3 0

3 years ago

What are the two ways in which pressure can be increased?

icang [17]

Raised temperature, decreased volume.

Temperature and Pressure are directly related, when volume increases so does the your pressure.

Volume and Pressure are indirectly related. When volume decreases, your pressure will increase.

7 0

3 years ago

Explain how you would decide which represents a greater mass: 3.25 x 1022 atoms of Ca or 2.45 grams of Mg?

elena55 [62]

Answer:

You need to convert the number of atoms of Ca into mass in grams, using Avogadro's number and the atomic mass of Ca.

Explanation:

The amount of matter is measured in grams. Thus, you need to convert the number of atoms of Ca (calcium) into mass to compare with 2.45 grams of Mg.

To convert the atoms of calcium into mass, you divide by Avogadro's number, to obtain the number of moles of atoms, and then divide by the atomic mass of calcium.

1. Number of moles, n

$n=\dfrac{\text{number of atoms}}{\text{Avogadro's number}}\\ \\ \\ n=\dfrac{3.25\times 10^{22}}{6.022\times 10^{23}}=0.053969mol$

2. Mass

mass = number of moles × atomic mass

mass = 0.053969mol × 40.078g/mol = 2.16g

Then, 2.45 g of Mg represent a greaer mass than the 3.25 × 10²² atoms of Ca.

4 0

3 years ago