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4 years ago

how many moles of potassium would you need to prepare 1200 grams of 5.0% potassium sulfate (m/m) solution

1 answer:

7 0

The moles of potassium that you would need to prepare 1200 g of 5% potassium sulfate solution is 1.538 moles

calculation
calculate the mass potassium using the below formula

%M/M = mass of the solute(potassium)/mass of the solvent (potassium sulfate solution)

let the mass of potassium be represented by Y

then convert % into fraction = 5/100

5/100 = Y/1200
cross multiplication
100y = 6000
divide both side by 100

Y= 60 g

moles of potassium =mass/molar mass

= 60/39=1.538

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SOMEONE PLEASE HELP

Zinaida [17]

Answer:

6. 7870 kg/m³ (3 s.f.)

7. 33.4 g (3 s.f.)

8. 12600 kg/m³ (3 s.f.)

Explanation:

6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.

1 kg= 1000g

1m³= 1 ×10⁶ cm³

Mass of iron bar

= 64.2g

= 64.2 ÷1000 kg

= 0.0642 kg

Volume of iron bar

= 8.16 cm³

= 8.16 ÷ 10⁶

$= 8.16 \times 10^{ - 6} \: kg$

$\boxed{density = \frac{mass}{volume} }$

Density of iron bar

$= \frac{0.0642}{8.16 \times 10^{ - 6} }$

= 7870 kg/m³ (3 s.f.)

$\boxed{mass = density \: \times volume}$

Mass

= 1.16 ×28.8

= 33.408 g

= 33.4 g (3 s.f.)

8. Volume of brick

= 12 cm³

$= 12 \times 10^{ - 6} \: m^{3} \\ = 1.2 \times 10^{ - 5} \: m ^{3}$

Mass of brick

= 151 g

= 151 ÷ 1000 kg

= 0.151 kg

Density of brick

= mass ÷ volume

$= \frac{0.151} {1.25 \times 10^{ - 5} } \\ = 12600 \: kg/ {m}^{3}$

(3 s.f.)

6 0

3 years ago

How many grams of Pb are contained in a mixture of 0.135 kg each of PbCl(OH) and Pb2Cl2CO3?

Dahasolnce [82]

Hey there!:

Given the mass of PbCl(OH) :

0.135 Kg = 0.135 Kg*(1000g / 1Kg) = 135 g

Molecular mass of PbCl(OH) = 207+35.5+16+1 = 259.5 g / mol

Atomic mass of Pb = 207 g/mol

Hence mass of Pb in 135 g PbCl(OH) :

(207 g Pb / 259.5 g PbClOH) * 135g PbClOH =

0.79768 * 135 => 107.68 g of Pb

For Pb2Cl2CO3 :

Given the mass of Pb2Cl2CO3 :

0.135 Kg = 0.135 Kgx(1000g / 1Kg) = 135 g

Molecular mass of Pb2Cl2CO3 = 2*207+2*35.5+12+3*16 = 545 g / mol

Mass of Pb present in 1 mol (=545 g / mol) of Pb2Cl2CO3 = 2*207 = 414 g

Hence mass of Pb in 135 g Pb2Cl2CO3:

(414 g Pb / 545 g PbClOH) * 135g PbClOH =

0.75963 * 135 => 102.55 g of Pb2Cl2CO3

Hope that helps!

8 0

3 years ago

Read 2 more answers

What is the total charge of the nucleus of a carbon atom?<br> (1) –6 (3) +6<br> (2) 0 (4) +12

NeX [460]

Carbon atomic number ⇒ 6
Carbon mass number ⇒ 12.

Carbon atomic number - Carbon mass number = number of neutrons.
12 - 6 = 6 neutrons.

Proton charge ⇒ +1

The total charge of the nucleus of a carbon atom ⇒⇒⇒ +6.

So the naswer is (3) +6

3 0

3 years ago

PLEASE ANSWER CORRECTLY AND ONLY IF U KNOW! IS IT A B C OR D?!

almond37 [142]

Answer:

Explanation:

There are three states of mater; solid liquid and gas. The sold state is the difficult to compress while the gaseous state is quite easy to compress.

A gas is easily compressed because the particles in a gas are far apart from each other. A solid is difficult to compress because the particles of a solid are close together. From all the above statements, it is easily deducible that the compressibility property of a substance in a particular state of matter depends on the proximity of the particles to each other, hence the answer above.

8 0

3 years ago

Find mass of 3 moles of water

EleoNora [17]

Answer:

54 g

Explanation:

1 mole of water = H2O

mass of 1 mole of H2O= mass of h2 + mass of o

= 2× mass of h +mass of o

= 2×1+16 =18 g

1 mole of water = 18g

3moles of water = 18×3g= 54g

6 0

3 years ago