All categories

3 years ago

Of the following elements, which could be classified as a metalloid (semimetal)? Select all that apply.

Chemistry

1 answer:

FromTheMoon [43]3 years ago

4 0

Answer:

(D) Si

(H) At

(J) B

Hope this helps!

You might be interested in

Dissolving 5.28 g of an impure sample of calcium carbonate in hydrochloric acid produced 1.14 L of carbon dioxide at 20.0 °C and

swat32

Answer:

$\%\ mass\ of\ CaCO_3=93.37\ \%$

Explanation:

Given that:

Pressure = 791 mmHg

Temperature = 20.0°C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (20 + 273.15) K = 293.15 K

T = 293.15 K

Volume = 100 L

Using ideal gas equation as:

PV=nRT

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 62.3637 L.mmHg/K.mol

Applying the equation as:

791 mmHg × 1.14 L = n × 62.3637 L.mmHg/K.mol × 293.15 K

⇒n of $CO_2$ produced = 0.0493 moles

According to the reaction:-

$CaCO_3 + 2 HCl\rightarrow CaCl_2 + H_2O + CO_2$

1 mole of carbon dioxide is produced 1 mole of calcium carbonate reacts

0.0493 mole of carbon dioxide is produced 0.0493 mole of calcium carbonate reacts

Moles of calcium carbonate reacted = 0.0493 moles

Molar mass of $CaCO_3$ = 100.0869 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$0.0493\ mol= \frac{Mass}{100.0869\ g/mol}$

$Mass_{CaCO_3}=4.93\ g$

Impure sample mass = 5.28 g

Percent mass is percentage by the mass of the compound present in the sample.

$\%\ mass\ of\ CaCO_3=\frac{Mass_{CaCO_3}}{Total\ mass}\times 100$

$\%\ mass\ of\ CaCO_3=\frac{4.93}{5.28}\times 100$

$\%\ mass\ of\ CaCO_3=93.37\ \%$

3 0

3 years ago

A glass of unsweetened lemonade has a mass of 255 grams. A spoonful of sugar is massed before stirring It Into the lemonade and

Alik [6]

Answer:

270

Explanation:

Once you add more mass to something the mass doesn’t go away you add more mass.

hope this helps!

7 0

2 years ago

What is biomolecules

sattari [20]

Biomolecules also called biological molecules, any of numerous substance that are produced by cells and living organisms

4 0

2 years ago

While in Europe, if you drive 125 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per lite

balu736 [363]

You would have spent $18.9

3 0

3 years ago

Read 2 more answers

If an electron fell to a lower orbit or energy level, energy would be

arsen [322]

It would emit energy in most of the cases in form of light

5 0

3 years ago

Read 2 more answers