Which one of the following reactions is NOT balanced?

Dimensional analysis, Plz hell I don’t understand and plz explain

Anastasy [175]

Explanation:

30 lb is 480 ounces

34 mi/second is 54.718 kilometre/ second

455 lb/ gal is 54521.024 grams / litre

50 cl is 500 millilitres

55nm is 5.5 × 10^-6 centimetre

7 0

3 years ago

How many moles are in 2.8x10^23 atoms of Calcium?

Zielflug [23.3K]

Answer: 1 mole ➡️ 6.022×10²³ atoms of si.

X mole ➡️ 2.8×10²⁴ atoms of si.

X = 2.8×10×10²³/6.022×10²³

= 28/6.022

= 4.65 moles.

Explanation:

8 0

3 years ago

Question List (4 items) (Drag and drop into the appropriate area) Find the volume of HCl that will neutralize the base. Find the

expeople1 [14]

The question is incomplete, the complete question is:

The solubility of slaked lime, $Ca(OH)_2$ , in water is 0.185 g/100 ml. You will need to calculate the volume of $2.50\times 10^{-3}$ M HCl needed to neutralize 14.5 mL of a saturated

<u>Answer:</u> The volume of HCl required is 290mL, the mass of $Ca(OH)_2$ is 0.0268g, the moles of

<u>Explanation:</u>

Given values:

Solubility of $Ca(OH)_2$ = 0.185 g/100 mL

Volume of $Ca(OH)_2$ = 14.5 mL

Using unitary method:

In 100 mL, the mass of $Ca(OH)_2$ present is 0.185 g

So, in 14.5mL. the mass of $Ca(OH)_2$ present will be = $\frac{0.185}{100}\times 14.5=0.0268g$

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

Given mass of $Ca(OH)_2$ = 0.0268 g

Molar mass of $Ca(OH)_2$ = 74 g/mol

Plugging values in equation 1:

$\text{Moles of }Ca(OH)_2=\frac{0.0268g}{74g/mol}=0.000362 mol$

Moles of $OH^-$ present = $(2\times 0.000362)=0.000724mol$

The chemical equation for the neutralization of calcium hydroxide and HCl follows:

$Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O$

By the stoichiometry of the reaction:

Moles of $OH^-$ = Moles of $H^+$ = 0.000724 mol

The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (mL)}}$ .....(2)

Moles of HCl = 0.000724 mol

Molarity of HCl = $2.50\times 10^{-3}$

Putting values in equation 2, we get:

$2.50\times 10^{-3}mol=\frac{0.000724\times 1000}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{0.000725\times 1000}{2.50\times 10^{-3}}=290mL$

Hence, the volume of HCl required is 290mL, the mass of $Ca(OH)_2$ is 0.0268g, the moles of

5 0

3 years ago

Rays used to take pictures of bones in the human body are:

Alexeev081 [22]

Answer:

B

Explanation:

Because when you go to the doctors they say, "You need to get your x-rays done" not microwave

5 0

3 years ago

What volume in L of a 0.724 M Nal solution contains 0.405 mol of Nal?

Setler [38]

Answer:

0.559 L

Explanation:

Step 1: Given data

Moles of sodium iodide (n): 0.405 mol

Molar concentration of sodium iodide (M): 0.724 M (0.724 mol/L)

Step 2: Calculate the volume of solution (V)

The molarity is equal to the moles of solute divided by the liters of solution.

M = n/V

V = n/M

V = 0.405 mol/(0.724 mol/L) = 0.559 L

4 0

2 years ago

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