_____ are the results of a thoroughly tested hypothesis?

Explain why soap needs to be used to clean clothes and why you can’t just use water alone?

Deffense [45]

Answer:

Water alone can't clean clothes because it won't attach to molecules of grease and dirt.

Explanation:

The surfactants it contains are made of molecules that have two different ends. One end is strongly attracted to water; the other is attracted to oily substances like grease.

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3 years ago

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Choose the best answer that completes the sentence. A complex ion contains _________________. Group of answer choices a central

STatiana [176]

Answer:

A complex ion contains a central metal ion bound to one or more ligands

Explanation:

A complex ion is consists of a central atom or ion, that is usually metallic, called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents.

An example of a complex ion is

[Co(NH3)6]3+

Please go through the attached file for a proper representation of the complex ion.

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3 years ago

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Calculate the silver ion concentration in a saturated solution of silver(i) sulfate (ksp = 1.4 × 10–5).

deff fn [24]

Answer:

= 0.030 M

Explanation:

We can take x to be the concentration in mol/L of Ag2SO4 that dissolves

Therefore; concentration of Ag+ is 2x mol/L and that of SO4^2- x mol/L.

Ksp = 1.4 x 10^-5

Ksp = [Ag+]^2 [SO42-]

= (2x)^2(x)

= 4x^3

Thus;

4x^3 = 1.4 x 10^-5

= 0.015 M

molar solubility = 0.015 M

But;

[Ag+]= 2x

Hence; silver ion concentration is

= 2 x 0.015 M

= 0.030 M

6 0

3 years ago

Calculate the volume of a 0.5M solution containing 20g of NaOH

Tju [1.3M]

Answer:

1L

Explanation:

First, let us calculate the number of mole present in 20g of NaOH. This is illustrated below:

Mass = 20g

Molar Mass of NaOH = 23 + 16 + 1 = 40g/mol

Number of mole =?

Number of mole = Mass /Molar Mass

Number of mole of NaOH = 20/40 = 0.5mol

From the question given, we obtained the following data:

Molarity = 0.5M

Mole = 0.5mole

Volume =?

Molarity = mole /Volume

Volume = mole /Molarity

Volume = 0.5/0.5

Volume = 1L

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A gas mixture with a total pressure of 745 mmHg contains each of the following gases at the indicated partial pressures: CO2, 24

Setler79 [48]

Answer:

For Part A: The partial pressure of Helium is 218 mmHg.

For Part B: The mass of helium gas is 0.504 g.

Explanation:

For Part A:

We are given:

$p_{CO_2}=245mmHg\\p_Ar}=119mmHg\\p_{O_2}=163mmHg\\P=745mmHg$

To calculate the partial pressure of helium, we use the formula:

$P=p_{CO_2}+p_{Ar}+p_{O_2}+p_{He}$

Putting values in above equation, we get:

$745=245+119+163+p_{He}\\p_{He}=218mmHg$

Hence, the partial pressure of Helium is 218 mmHg.

For Part B:

To calculate the mass of helium gas, we use the equation given by ideal gas:

PV = nRT

or,

$PV=\frac{m}{M}RT$

where,

P = Pressure of helium gas = 218 mmHg

V = Volume of the helium gas = 10.2 L

m = Mass of helium gas = ? g

M = Molar mass of helium gas = 4 g/mol

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of helium gas = 283 K

Putting values in above equation, we get:

$218mmHg\times 10.2L=\frac{m}{4g/mol}\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 283K\\\\m=0.504g$

Hence, the mass of helium gas is 0.504 g.

6 0

3 years ago