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2 years ago

How many grams of sodium hydroxide, NaOH, are needed to make 355.0 mL of a 4.75M solution? The molar mass of NaOH is 40.00 g/mol

Chemistry

1 answer:

Katen [24]2 years ago

8 0

Answer:

4198.97404999

Explanation:

In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.

Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.

If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.

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3. If you start with 8x1025 molecules of Cl, and 25 grams of KI, how many grams of KCl would

miskamm [114]

Answer:

Percent yield = 89.1%

Explanation:

Based on the equation:

Cl₂ + 2KI → 2KCl + I₂

1 mole of Cl₂ reacts with 2 moles of KI to produce to moles of KCl

To solve this quesiton we must find the moles of each reactant in order to find the limiting reactant. With the limiting reactant we can find the moles of KCl and the mass:

Moles Cl₂:

8x10²⁵ molecules * (1mol / 6.022x10²³ molecules) = 133 moles

Moles KI -Molar mass: 166.0028g/mol-

25g * (1mol / 166.0028g) = 0.15 moles

Here, clarely, the KI is the limiting reactant

As 2 moles of KI produce 2 moles of KCl, the moles of KCl produced are 0.15 moles. The theoretical mass is:

0.15 moles * (74.5513g / mol) =

11.2g KCl

Percent yield is: Actual yield (10.0g) / Theoretical yield (11.2g) * 100

<h3>Percent yield = 89.1%</h3>

3 0

3 years ago

If the solubility of sugar at 25ºC is 211 g/100 g H2O, what mass of sugar can be dissolved in 300 g of H2O?

ladessa [460]

Answer:

633 grams of sugar can be dissolved in 300 g of H₂O

Explanation:

Solubility is the measure of the ability of a certain substance to dissolve in another and form a homogeneous system. Solubility is then the maximum amount of a solute that a solvent can receive and is expressed by concentration units.

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

a ⇒ b

c ⇒ x

Then:

$x=\frac{c*b}{a}$

You can apply the rule of three as follows: if by definition of solubility in 100 grams of H₂O there are 211 grams of sugar, in 300 g of H₂O how much sugar is there?

$sugar=\frac{300 grams of H_{2}O *211 grams of sugar}{100 grams of H_{2}O}$

sugar= 633 grams

633 grams of sugar can be dissolved in 300 g of H₂O

7 0

3 years ago

Read 2 more answers

The total variety of organisms that live in the biosphere

RUDIKE [14]

The sum total of the genetically based variety of living organisms in the biosphere is called a. species diversity. c. biodiversity.

8 0

3 years ago

Read 2 more answers

List 3 particles of an atom (w/their symbol & charge)

Ulleksa [173]

Answer:

there are three fundamental particles of atom

which are :

proton ( positively charged (+) )
electron ( negatively charged ( - ) )
neutron ( having no charge on it ( neutral ))

Particle Symbol

electron =》e-

proton =》p+

neutron =》n°

6 0

2 years ago

A patient needs to be given exactly 1000 ml of a 5.0% (w/v) intravenous glucose solution. the stock solution is 55% (w/v). how m

LiRa [457]

The patient needs 1000 ml of 5% (w/v) glucose solution
i.e 1000 ml x 5 g/ 100 ml
where the stock solution is 55% (w/v) = 55 g / 100 ml
So, 1000 ml x 5 g / 100 ml = V (ml) x 55 g / 100 ml
V = 1000 x (5 / 100) / (55 / 100) = 5000 / 55 = 90.9 ml
∴ the patient needs 90.9 ml of 55% (w/v) glucose solution

6 0

3 years ago