I don’t know how to solve this

Chemistry

1 answer:

stepladder [879]3 years ago

7 0

Hi,

Answer is 191.2.

800J = 191.2 cal

Hope this helps.

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A mixture 21.7 g NaCl 3.74 g kcl and 9.76 g licl how many moles of nacl are in this mixture

slava [35]

Moles (mol) = mass (g) / molar mass (g/mol)

Mass of NaCl = 21.7 g
Molar mass of NaCl = 58.4 g/mol
Hence, moles of NaCl = 21.7 g / 58.4 g/mol = 0.372 mol

Hence moles of NaCl in the mixture is 0.372 mol.

Let's assume that mixture has only given compounds and free of impurities.
Then, we can present this as a mole percentage.

mole % = (moles of desired substance / Total moles of the mixture) x 100%

Hence,
mole % of NaCl = (moles of NaCl / Total moles of the mixture) x 100%

Total moles of mixture = moles of NaCl + KCl + LiCl

Mass of KCl = 3.74 g
Molar mass of NaCl = 74.6 g/mol
Hence, moles of NaCl = 3.74 g / 74.6 g/mol = 0.050 mol

Mass of NaCl = 9.76 g
Molar mass of NaCl = 42.4 g/mol
Hence, moles of NaCl = 9.76 g / 42.4 g/mol = 0.230 mol

Total moles = 0.372 mol + 0.050 mol + 0.230 mol = 0.652 mol

mole % of NaCl = (moles of NaCl / Total moles of the mixture) x 100%
= (0.372 mol / 0.652 mol) x 100%
= 57.06%

Hence, mixture has 57.06% of NaCl as the mole percentage.

8 0

3 years ago

Perform each of the following unit conversions using the conversion factors given below: 1 atm = 760 mmHg = 101.325 kPa

Alenkasestr [34]

unit coversation
1.429 atm - 1086mmhg

9361 pa-9.36 KPa - 70.21 mmhg

725 mmhg -0.95 atm- 96.26 kpa

calculation

(a) 1 atm = 760 mmhg
1.429 atm = ?
1.429 x760/1 = 1086.34 mm hg

(B) 1 mmhg = 101.325 kpa
? =9361 KPa
9361 x1 /101.25 =70.21 mmhg

760 mm hg= 101.325 KPa
70.21 mm hg=?

70.21 x101.325/760 = 9.36 Kpa

(C ) 1 atm = 760 mmhg
? = 725
= 725 x1/ 760=0.95 atm

1 atm = 101.325 kpa
0.95 =?

0.95 x101.325/1 = 96.26 KPa

5 0

4 years ago

Read 2 more answers

Krypton is named after the Greek word that means “secret.” Which explains why krypton was most likely given this name?

irinina [24]

Answer:

<h2>Krypton is a halogen, so it should be kept secret because it is so reactive and toxic. Krypton is a noble gas, so it was difficult for chemists to find it, as though it was a secret.</h2>

Explanation: