___________ currents in the Earth's mantle cause plate movement which causes earthquakes and volcanic activity

Which of the following steps correctly describes the preparation of 0.5 M solution of FeCl3?

Marizza181 [45]

Answer:

Option A is correct

Explanation:

Data given:

Steps for preparation of 0.5 M solution = ?

Solution:

Molarity: This the term used for the concentration of the solution. It is the amount of solute in moles dissolve in 1 Liter of solution.

Formula used for Molarity

Molarity = number of moles of solute / 1 L of solution

From the above definition and formula it is clear that we have to know the following things.

no. of moles of f the solute

we also should know that of what concentration we are preparing solution in terms of molarity
The total amount of should be in liter of solution not solvent separately

Now:

As we couldn't weight mole on balance so have to convert moles to grams by using molar mass or mass in grams formula

As

1 mole = mass in grams / molar mass

so to convert mole to mass rearrange the above equation

mass in grams = 1 mole x molar mass

So,

1 mole of any substance equal to its molar mass

Now, to prepare 0.5 M solution of FeCl₃

First we find molar mass and weigh it

So,

1 mole of FeCl₃ = molar mass of FeCl₃

for 0.5 M

Multiply the molar mass with 0.5

To make 1 L of solution

As we know that molarity is the amount of solution in liter of solution not solvent, so we add the calculated amount of solute in volumetric flask and then add water till the 1 L mark. that is amount of solute plus solvent combined form 1 L of Solution.

So, Option A is correct: Find the molar mass of FeCl3 and multiply by 0.5 to find the amount. Add this amount in a volumetric flask and add water till the 1 L mark

3 0

3 years ago

What functional group consists of a carbon atom double-bonded to an oxygen atom?

DaniilM [7]

Answer:

The answer to your question is: letter B.

Explanation:

Carbon atom double-bonded to an oxygen atom C= O,

a) Carbohydrate group this group does not exist

b)Carbonyl group This option is right, carbonyl group is C=O

c) Hydroxyl group This option is incorrect, hydroxyl group is OH, very different from C=O

d) Ketone group Ketone group does not exist, ketones have the same functional group as aldehydes (C=O)

7 0

3 years ago

Read 2 more answers

When performing a gram stain, it is necessary to remove crystal violet stain from any gram negative bacteria on the slide. Micro

Snezhnost [94]

Answer:

10.11 mL

Explanation:

Given that :

Total volume of decolorizer = 500 mL

A common recipe is equal parts 95% ethanol and acetone.

So;

The volume of 95% ethanol in the decolorizer = 500mL/2 = 250 mL

Let represent V(ml) for the 99% of ethanol needed to make 95% of the 250 mL of ethanol;

Therefore:

V(ml) × 0.99 = 250 × 0.95

V(ml) × 0.99 = 237.5

V(ml) = 237.5/0.99

V(ml) = 239.89 mL

Hence; the amount of water to be added to 95% of ethanol = ( 250 - 239.89 )mL = 10.11 mL

5 0

3 years ago

A 51.0 mL aliquot of a 1.50 M solution is diluted to a total volume of 208 mL. A 104 mL portion of that solution is diluted by a

S_A_V [24]

Answer:

The final concentration is 0.226 M.

Explanation:

In this problem the dilution has occurred two times. So the symbol initial concentration, concentration after first dilution and the concentration after second dilution is given as C1, C2, and C3 respectively. Same can be done for the volume i.e, V1, V2, and V3 will be the initial volume, the volume taken after first dilution, and the volume after second dilution.

So, let's use the dilution formula for the first dilution

$C_1 \times V_1 = C_2 \times V_2$