All categories

3 years ago

PLS help

Chemistry

2 answers:

Pani-rosa [81]3 years ago

6 0

Answer:

Sc2O5

Explanation:

We must first consider the relative valencies of the elements. Recall that the formulae of the compound must involve an exchange in the valencies of the two combining species. Hence the first step in solving the problem must be to put down the individual valencies of the both elements then exchange thief valencies to obtain the actual formula of the compound formed by a combination of the both species as we shall show below;

Oxygen=2

Scandium= 5

When the both exchange their valencies

Scandium= 2

Oxygen=5

Hence the formula of the compound will be Sc2O5

viktelen [127]3 years ago

3 0

Answer:

d . Sc2O5

Explanation:

Hello,

In this case, when forming oxides from a metal and oxygen, for us to find out each element's subscript, we must exchange them as shown below, considering +5 for scandium:

$Sc^{+5}_2O^{-2}_5$

For that reason, the answer is d . Sc2O5

Best regards.

You might be interested in

A sample of vinegar was found to have an acetic acid concentration of 0.8846 m. What is the acetic acid % by mass? Assume the de

jenyasd209 [6]

Answer:

5.3%

Explanation:

Let the volume be 1 L

volume , V = 1 L

use:

number of mol,

n = Molarity * Volume

= 0.8846*1

= 0.8846 mol

Molar mass of CH3COOH,

MM = 2*MM(C) + 4*MM(H) + 2*MM(O)

= 2*12.01 + 4*1.008 + 2*16.0

= 60.052 g/mol

use:

mass of CH3COOH,

m = number of mol * molar mass

= 0.8846 mol * 60.05 g/mol

= 53.12 g

volume of solution = 1 L = 1000 mL

density of solution = 1.00 g/mL

Use:

mass of solution = density * volume

= 1.00 g/mL * 1000 mL

= 1000 g

Now use:

mass % of acetic acid = mass of acetic acid * 100 / mass of solution

= 53.12 * 100 / 1000

= 5.312 %

≅ 5.3%

3 0

3 years ago

8 Fe + Sg → 8 Fes How many grams of FeS is produced from 0.3 mol Sg?

frozen [14]

Answer:

Explanation:

Molar ratio for Sg : FeS = 1:8

If there are 0.3 moles for Sg

Therefore, 0.3 × 8 =2.4 moles of FeS

Mass = Moles/ Mr

Mr of FeS = 56+32=88

So mass = 2.4/88

Mass= 0.027g

6 0

3 years ago

When 125 grams of FeO react with 25.0 grams of Al, how many grams of Fe can be produced? FeO + Al → Fe + Al2O3 25.9 g Fe 38.7 g

Serga [27]

Answer: The mass of iron produced will be 77.6 grams

Explanation:

To calculate the number of moles, we use the equation:

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

For FeO:

Given mass of FeO = 125 g

Molar mass of FeO = 71.8 g/mol

Putting values in equation 1, we get:

$\text{Moles of FeO}=\frac{125g}{71.8g/mol}=1.74mol$

For aluminium:

Given mass of aluminium = 25.0 g

Molar mass of aluminium = 27 g/mol

Putting values in equation 1, we get:

$\text{Moles of aluminium}=\frac{25.0g}{27g/mol}=0.93mol$

The given chemical reaction follows:

$3FeO+2Al\rightarrow 3Fe+Al_2O_3$

By Stoichiometry of the reaction:

2 moles of aluminium metal reacts with 3 mole of FeO

So, 0.93 moles of aluminium metal will react with = $\frac{3}{2}\times 0.93=1.395mol$ of FeO

As, given amount of FeO is more than the required amount. So, it is considered as an excess reagent.

Thus, aluminium metal is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of aluminium metal produces 3 mole of iron metal

So, 0.93 moles of aluminium metal will produce = $\frac{3}{2}\times 0.93=1.395moles$ of iron metal

Now, calculating the mass of iron metal from equation 1, we get:

Molar mass of iron = 55.85 g/mol

Moles of iron = 1.395 moles

Putting values in equation 1, we get:

$1.395mol=\frac{\text{Mass of iron}}{55.85g/mol}\\\\\text{Mass of iron}=(1.395mol\times 55.85g/mol)=77.6g$

Hence, the mass of iron produced will be 77.6 grams

4 0

3 years ago

What is a zone of weak, variable winds located at 30 degrees north and 30 degrees south?

timurjin [86]

Answer:

Horse latitude, trade winds

Explanation:

The area of the low pressure or the calm consists of the variable light winds that blow near the equator are known to the marines as the doldrums and they form a circuital pattern near the earth atmosphere.

Forms at a center of the near the higher pressure systems called as the horse latitudes where the trade winds at the surface are weak and variable and this zone is found generally in latitudes of the 30° North and South of the equator and move in an east to west direction.

4 0

3 years ago

How does ur body maintain constant tempature on a hot day?

Lina20 [59]

It knows that when water evaporates, it carries heat energy away with it.
So your body puts some water out on your skin, and hopes that it will
evaporate. We call that "perspiring" or "sweating".

8 0

3 years ago

Read 2 more answers