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Please help I am so bad at chemistry!!

Please help I am so bad at chemistry!!-example-1
User Jayde
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1 Answer

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Answer:

The answer to your question is below

Step-by-step explanation:

Data

3.- grams of reactant

volume = 1l

a) 0.5 M NaCl

-Calculate the number of moles

moles = Molarity x volume

moles = 0.5 x 1

moles = 0.5

-Calculate the molar mass of NaCl

NaCl = 23 + 35.5 = 58.5 g

58.5g ------------------ 1 mol

x ------------------0.5 mol

x = (0.5 x 58.5) / 1

x = 29.25 grams of NaCl

b)

-Calculate the moles

moles = 2 x 1

moles = 2

-Calculate the molar mass of CaCl₂

CaCl₂ = 40 + 71 = 142 g

-Calculate the grams

142 g ----------------- 1 mol

x ---------------- 2 moles

x = (2 x 142) / 1

x = 284 grams of CaCl₂

c) 1.5 M NaOH

-Calculate the moles of NaOH

moles = 1.5 x 1

moles = 1.5

-Calculate the molar mass of NaOH

NaOH = 23 + 16 + 1 = 40 g

-Calculate the grams

40 g --------------- 1 mol

x --------------- 1.5 moles

x = (1.5 x 40)

x = 60 grams of NaoH

4.- mass of fructose = ?

Volume = 1l

Molarity = 0.75

-Calculate the moles of fructose

moles = 0.75 x 1

moles = 0.75

-Calculate the molar mass of fructose

C₆H₁₂O₆ = (12 x 6) + (12 x 1) + (16 x 6) = 72 + 12 + 96

= 180 g

-Calculate the grams of fructose

180 g ---------------- 1 mol

x ---------------0.75 moles

x = (0.75 x 180) / 1

x = 135 g of fructose

5.- Balanced chemical reaction

3Ba(NO₃)₂ + Al₂(SO₄)₃ ⇒ 3BaSO₄ + 2Al(NO₃)₃

-Calculate the moles of Al₂(SO₄)₃

moles = molarity x volume

moles = 0.35 x 0.025

= 0.00875

-Use proportions to calculate the moles of Ba(NO₃)₂

3 moles of Ba(NO₃)₂ ----------------- 1 mol of Al(SO₄)₃

x -----------------0.00875 moles of Al(SO₄)₃

x = (0.00875 x 3) / 1

x = 0.02625

-Calculate the volume of 0.280 M solution of Ba(NO₃)₂

volume = moles / molarity

volume = 0.02625 / 0.280

volume = 0.0938 l or 93.8 ml

5.- Balanced chemical reaction

2AgNO₃ + CaBr₂ ⇒ 2AgBr + Ca(NO₃)₂

- Calculate the moles of CaBr₂

moles = 0.128 x 0.035 = 0.0045

- Calculate the moles of AgNO₃

2 moles of AgNO₃ ------------------- 1 mol of CaBr₂

x -------------------0.0045 moles

x = (0.0045 x 2) /1

x = 0.009 moles

- Calculate the volume of AgNO₃

Volume = moles / Molarity

= 0.009 / 0.415

= 0.0215 l or 21.6 ml

User TeeZee
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