Which diagram represents a physical change,only?

An unknown solid acid is either citric acid or tartaric acid. To determine which acid you have, you titrate a sample of the soli

Norma-Jean [14]

Answer:

The unknown acid is citric acid.

Explanation:

Based on the reactions:

Citric acid: H3C6H5O7(aq) + 3NaOH (aq) → 3H2O (l) + Na2C6H5O7 (aq)

Tartaric acid: H2C4H4O6 (aq) + 2NaOH (aq) → 2H2O (l) + Na2C4H4O6 (aq)

0.956g of sample if tartaric acid requires:

0.956g × (1mol / 150,087 g) = 0.006370 moles of tartaric acid. As 1 mole reacts with 2 moles of NaOH:

0.006370 moles of tartaric acid × (2 mol NaOH / 1 moles tartaric acid) = 0.0127 moles of NaOH. As the concentration of the NaOH is 0.513M:

0.0127 moles of NaOH × (1L / 0.513mol) = 0.0248L ≡ 24.8mL

Now, 0.956g of citric acid requires:

0.956g × (1mol / 192,124g) = 0.004976 moles of citric acid. As 1 mole reacts with 3 moles of NaOH:

0.004976 moles of citric acid × (3 mol NaOH / 1 moles tartaric acid) = 0.0149 moles of NaOH. As the concentration of the NaOH is 0.513M:

0.0149 moles of NaOH × (1L / 0.513mol) = 0.0291L ≡ 29.1mL

As the titration requires 29.1mL of the base, the unknown acid is citric acid.

5 0

3 years ago

Read 2 more answers

Which of the following determines the identity of an element?

nalin [4]

B mass number because it can be observed with out changing the element

4 0

3 years ago

Cl is highly reactive. We know NaCl to

love history [14]

I think the answer to that is B

8 0

3 years ago

H₂C=CH-CH₂-CH=CH₂ how many single and double bonds

nikklg [1K]

Answer:

2 double bonds 2 single bonds

5 0

4 years ago

Read 2 more answers

Iron(III) oxide reacts with carbon monoxide to produce iron and carbon; Fe2O3(s)+3CO(g)-->2Fe(s)+3CO2(g). a) What is the perc

VMariaS [17]

Answer:

a) %yield= 33.00 %

b) %yield= 72.1 %

Explanation:

Step 1: Data given

Mass of iron(III) oxide = 65.0 grams

mass of iron produced = 15.0 grams

Molar mass of Fe2O3 = 159.69 g/mol

Molar mass of CO = 44.01 g/mol

Step 2: The balanced equation:

Fe2O3(s)+3CO(g) →2Fe(s)+3CO2(g)

Step 3: Calculate moles of Fe2O3

Moles Fe2O3 = 65.0 grams / 159.69 g/mol

Moles Fe2O3 = 0.407 moles

Step 4: Calculate moles Fe

For 1 mole Fe2O3 we'll have 2 moles Fe

For 0.407 moles Fe2O3 we'll have 2*0.407 = 0.814 molesFe

Step 5: Calculate mass Fe

Mass fe = 0.814*55.845 g/mol

Mass Fe = 45.46 grams = theoretical yield

Step 6: Calculate % yield

%yield = (actual yield/theoretical yield)*100%

%yield = (15.0/45.46)*100%

%yield= 33.00 %

b) What is the percent yield for the reaction if 75.0 g of carbon monoxide produces 85.0 g of carbon dioxide?

Step 1: Data given

Mass of CO = 75.0 grams

mass of CO2 produced = 85.0 grams

Molar mass of CO = 28.01 g/mol

Molar mass of CO2 = 44.01 g/mol

Step 2: The balanced equation:

Fe2O3(s)+3CO(g) →2Fe(s)+3CO2(g)

Step 3: Calculate moles of CO

Moles CO = 75.0 grams / 28.01 g/mol

Moles CO = 2.68 moles

Step 4: Calculate moles CO2

For 1 mole Fe2O3 we need 3 moles CO to produce 2 moles Fe and 3 moles CO2

For 2.68 moles CO we'll have 2.68 moles CO2

Step 5: Calculate mass CO2

Mass CO2= 2.68 * 44.01 g/mol

Mass CO2 = 117.95 grams = theoretical yield

Step 6: Calculate % yield

%yield = (actual yield/theoretical yield)*100%

%yield = (85.0/117.95)*100%

%yield= 72.1 %

7 0

4 years ago