Where are metals on the table?

How many milliliters of water are needed to prepare a 3.5M solution of NaOH if you have .5mol of the solute

Mamont248 [21]

Answer:

1335.12 mL of H2O

Explanation:

To calculate the mililiters of water that the solution needs, it is necessary to know that the volume of the solution is equal to the volume of the solute (NaOH) plus the volume of the solvent (H2O).

From the molarity formula we can first calculate the volume of the solution:

$M=\frac{solute moles}{solution volume}$

$Solutionvolume=\frac{solute moles}{M} =\frac{5mol}{3.5\frac{mol}{L} } =1.429L$

The volume of the solution as we said previously is:

Solution volume = solute volume + solvent volume

To determine the volume of the solute we first obtain the grams of NaOH through the molecular weight formula:

$MW=\frac{mass}{mol}$

$Mass=MW*mol=39.997\frac{g}{mol} *5mol=199.985g$

Now with the density of NaOH the milliliters of solute can be determined:

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

$Volume=\frac{mass}{d} =\frac{199.985g}{2.13\frac{g}{mL} } =93.88mL of NaOH$

Having the volume of the solution and the volume of the solute, the volume of the solvent H2O can be calculated:

Solvent volume = solution volume - solute volume

Solvent volume = 1429 mL - 93.88 mL = 1335.12 mL of H2O

7 0

3 years ago

Acid & Base Calculations Calculate the hydronium ion concentration for each. Tell whether it is an acid or a base. 1. pH = 5

Anuta_ua [19.1K]

Explanation:

pH is the negative logarithm of hydronium ion concentration present in a solution.

If the solution has high hydrogen ion concentration, then the pH will be low and the solution will be acidic. The pH range of acidic solution is 0 to 6.9
If the solution has low hydrogen ion concentration, then the pH will be high and the solution will be basic. The pH range of basic solution is 7.1 to 14
The solution having pH equal to 7 is termed as neutral solution.

To calculate the pH of the solution, we use equation:

$pH=-\log[H_3O^+]$ ......(1)

To calculate the pOH of the solution, we use the equation:

pH + pOH = 14 ........(2)

For 1:

We are given:

pH = 5.54

Putting values in equation 1, we get:

$5.54=-\log[H_3O^+]$

$[H_3O^+]=2.88\times 10^{-6}M$

Now, putting values in equation 2, we get:

14 = 5.54 + pOH

pOH = 8.46

The solution is acidic in nature.

For 2:

We are given:

pOH = 9.7

Putting values in equation 2, we get:

14 = 9.7 + pH

pH = 4.3

Now, putting values in equation 1, we get:

$4.3=-\log[H_3O^+]$

$[H_3O^+]=5.012\times 10^{-5}M$

The solution is acidic in nature.

For 3:

We are given:

pH = 7.0

Putting values in equation 1, we get:

$7.0=-\log[H_3O^+]$

$[H_3O^+]=1.00\times 10^{-7}M$

Now, putting values in equation 2, we get:

14 = 7.0 + pOH

pOH = 7.0

The solution is neither acidic nor basic in nature.

For 4:

We are given:

pH = 12.9

Putting values in equation 1, we get:

$12.9=-\log[H_3O^+]$

$[H_3O^+]=1.26\times 10^{-13}M$

Now, putting values in equation 2, we get:

14 = 12.9 + pOH

pOH = 1.1

The solution is basic in nature.

For 5:

We are given:

pOH = 1.2

Putting values in equation 2, we get:

14 = 1.2 + pH

pH = 12.8

Now, putting values in equation 1, we get:

$12.8=-\log[H_3O^+]$

$[H_3O^+]=1.58\times 10^{-13}M$

The solution is basic in nature.

For 6:

We are given:

$[H_3O^+]=1\times 10^{-5}M$

Putting values in equation 1, we get:

$pH=-\log(1\times 10^{-5})$

$pH=5$

Now, putting values in equation 2, we get:

14 = 5 + pOH

pOH = 9

The solution is acidic in nature.

5 0

3 years ago

Explain why water is polar. Check all that apply. View Available Hint(s) Water is known as a polar molecule because Check all th

sineoko [7]

Answer:

The correct statements that you must check are:

The oxygen atom has a greater attraction for electrons than the hydrogen atom does (second statement).

The electrons of the covalent bond are not shared equally between the hydrogen and oxygen atoms (fourth statement).

Explanation:

Electronegativity is the relative ability of an atom to pull the electrons in a covalent bond.

Hydrogen has an electronegativity of 2.20 and oxygen has 3.44. That means that oxygen attracts the electrons more strongly than hydrogen does (second statement).

As consequence, the electrons in the covalent bond H - O of water are not shared equally (fourth statement): the electron density will be higher around the O atoms.

Of course, this discards the statement telling that hydrogen atom attracts electrons much more strongly than the oxygen atom, and the statement telling that hydrogen and oxigen have same electronegativity.

Such difference in electron densities creates a dipole moment, so you discard the last statement (that the water dipole moment is equal to zero).

7 0

3 years ago

For an alloy that consists of 33.5 wt% Pb and 66.5 wt% Sn, what is the composition (a) of Pb (in at%), and (b) of Sn (in at%)? T

Tju [1.3M]

Answer:

Pb: 22.4 at%

Sn: 77.6 at%

Explanation:

It is possible to find at% of Pb and Sn converting mass in moles using molar mass assuming a basis of 100g, thus:

Pb: 33.5g × (1mol / 207.2g) = 0.1617mol

Sn: 66.5g × (1mol / 118.7g) = 0.5602mol

Total moles: 0.1617mol + 0.5602mol = 0.7219mol

Composition in at%:

Pb: 0.1617mol / 0.7219mol × 100 = 22.4 at%

Sn: 0.5602mol / 0.7219mol × 100 = 77.6 at%

I hope it helps!

5 0

3 years ago

Oxygen is denoted as 16O *. How many protons and neutrons does an oxygen atom have?

Lena [83]

I believe the oxygen atom has 8 protons and 8 neutrons.

7 0

2 years ago

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