Which statement accurately describes radioactive dating?

Photosynthesis uses all of the following except __ to make food ?

Harman [31]

What are the options

7 0

3 years ago

Suppose you are working with a NaOH stock solution but you need a solution with a lower concentration for your experiment. Calcu

Monica [59]

Answer: The volume of the 1.224 M NaOH solution needed is 26.16 mL

Explanation:

In order to prepare the dilute NaOH solution, solvent is added to a given amount of the NaOH stock solution up to a final volume of 250.0 mL.

Since only solvent is added, the amount of the solute, NaOH, in the dilute solution is the same as in the volume taken from the stock solution.

Molarity (M) is calculated from the following equation:

M = n ÷ V

where n is the number of moles of the solute in the solution, and V is the volume of the solution.

Accordingly, the number of moles of the solute is given by

n = M x V

Now, let's designate the stock NaOH solution and the dilute solution as (1) and (2), respectively . The number of moles of NaOH in each of these solutions is:

n (1) = M (1) x V (1)

n (2) = M (2) x V (2)

As the amount of NaOH in the dilute solution is the same as in the volume taken from the stock solution,

n (1) = n (2)

and

M (1) x V (1) = M (2) x V (2)

For the stock solution, M (1) = 1.244 M, and V (1) is the volume needed. For the dilute solution, M (2) = 0,1281 M, and V (2) = 250.0 mL.

The volume of the stock solution needed, V (1), is calculated as follows:

V (1) = M (2) x V (2) ÷ M (1)

V (1) = 0.1281 M x 250.0 mL ÷ 1.224 M

V (1) = 26.16 mL

The volume of the 1.224 M NaOH solution needed is 26.16 mL.

7 0

3 years ago

A solution is prepared by adding 1.43 mol of kcl to 889 g of water. the concentration of kcl is ________ molal. a solution is pr

s344n2d4d5 [400]

A solution is prepared by adding 1.43 mol of potassium chloride (kcl) to 889 g of water. The concentration of kcl is 1.61 molal.
mol of Kcl (potassium chloride)= 1.43
water = 889 g
the formula for calculating molality is:
molality = moles of solute/kilograms of solvent
1kg = 1000g so, 889g = 0.889kg

m = 1.43/0.889 = 1.61 molal

7 0

3 years ago

Please help me out i will give you brainlist. 0.500 is wrong

Alik [6]

<h3>Answer: b) 0.250 mol</h3>

============================================

Work Shown:

Using the periodic table, we see that

1 mole of carbon = 12 grams
1 mole of oxygen = 16 grams

These are approximations and these values are often found underneath the atomic symbol. For example, the atomic weight listed under carbon is roughly 12.011 grams. I'm rounding to 2 sig figs in those numbers listed above.

So 1 mole of CO2 is approximately 12+2*16 = 44 grams. The 2 is there since we have 2 oxygens attached to the carbon atom.

-------------------

Since 1 mole of CO2 is 44 grams, we can use that to convert from grams to moles.

11.0 grams of CO2 = (11.0 grams)*(1 mol/44 g) = (11.0/44) mol = 0.250 mol of CO2

In short,

11.0 grams of CO2 = 0.250 mol of CO2

This is approximate.

We don't need to use any of the information in the table.

3 0

3 years ago

Read 2 more answers

Match the salt with the acid and base used to form it in a neutralizing reaction. K2SO4

emmasim [6.3K]

Answer:

KOH and H₂SO₄

Explanation:

Neutralization reaction:

It is the reaction in which acid and base react with each other and produce salt and water.

For example:

2KOH + H₂SO₄ → K₂SO₄ + 2H₂O

1. Potassium hydroxide and sulfuric acid react to produce potassium sulfate salt and water.

2. Potassium hydroxide and phosphoric acid react to produce potassium phosphate and water.

H₃PO₄ + 3KOH → K₃PO₄ + 3H₂O

3. Phosphoric acid sodium hydroxide react to produce sodium phosphate and water.

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

3 0

3 years ago

Read 2 more answers