Q: What is the number who chose Italian dressing?

Answer: The number of customers who chose Italian dressing is 90. Explanation: This problem involves understanding the distribution of salad dressing choices among customers, which is represented by a circle graph (pie chart). The key concepts involved are percentage calculations and proportions. The problem asks to find the difference in the number of customers choosing Italian dressing and vinaigrette dressing, given the total number of customers and the percentage distribution. The method involves: Calculating the number of customers for each dressing based on the percentage. Finding the difference between the two numbers. Steps: Identify the total number of customers: Total customers = 200 Determine the percentage for Italian dressing: From the table, Italian dressing = 45% Calculate the number of customers who chose Italian dressing: \[ \text{Number of Italian dressing customers} = \frac{45}{100} \times 200 = 0.45 \times 200 = 90 \] Determine the percentage for Vinaigrette dressing: Vinaigrette = 30% Calculate the number of customers who chose Vinaigrette dressing: \[ \frac{30}{100} \times 200 = 0.30 \times 200 = 60 \] Find the difference between Italian and Vinaigrette dressing customers: \[ 90 - 60 = 30 \] Question asks for the difference between the number who chose Italian dressing and the number who chose vinaigrette dressing: The difference is 30. Note: The question also mentions the number who chose vinaigrette dressing, but the main calculation is to find the number for Italian dressing, which is 90.

Question

Which formula/name pair is incorrect? A) FeSO4 iron(II) sulfate B) Fe2(SO3)3 iron(III) sulfate C) FeS iron(II) sulfide D) FeSO3 iron(II) sulfide E) Fe2(SO4)3 iron(III) sulfide

Accepted Answer

Answer: The incorrect pair is B) Fe₂(SO₃)₃ iron(III) sulfite.

Explanation:  This question involves understanding chemical nomenclature and the formulas corresponding to the names of chemical compounds, especially those involving transition metals and polyatomic ions. The key concepts include oxidation states, the naming conventions for ionic compounds, and the correct formulas for sulfites and sulfates.

The name "iron(III) sulfite" indicates iron in the +3 oxidation state and sulfite as the anion, which has the formula SO₃²⁻.  
To form a neutral compound, the total positive charge from iron must balance the total negative charge from sulfite ions.  
For iron(III) sulfite, the formula should be Fe₂(SO₃)₃ because:  
Each Fe³⁺ ion contributes +3, so two Fe³⁺ ions contribute +6.  
Each SO₃²⁻ ion contributes -2, so three sulfite ions contribute -6.  
The charges balance: $2 \times +3 + 3 \times -2 = 0$.

The mistake in option B is that it correctly states the formula as Fe₂(SO₃)₃, which is correct for iron(III) sulfite. However, the question asks which pair is incorrect, implying that the pair's name and formula do not match. Since the name "Fe₂(SO₃)₃" correctly corresponds to "iron(III) sulfite," the pair is correct.

But, if we analyze the options carefully, the actual incorrect pair is A) because FeSO₄ is iron(II) sulfate, not sulfite.

FeSO₄ corresponds to iron(II) sulfate, not sulfite, so the name should be "iron(II) sulfate," not sulfite.

Therefore, the correct answer is:  A) FeSO₄ (iron(II) sulfate), because the name and formula do not match the "sulfite" description.

Full Steps:

Identify the ions involved:

Sulfite ion: $SO_3^{2-}$
Sulfate ion: $SO_4^{2-}$

Determine oxidation states:

For sulfite: sulfur is +4 (since $3 \times -2 + (+4) = -2$)
For sulfate: sulfur is +6

Match names to formulas:

"iron(III) sulfite" should have Fe in +3 oxidation state and sulfite ions: formula $Fe_2(SO_3)_3$
"iron(II) sulfate" should have Fe in +2 oxidation state and sulfate ions: formula $FeSO_4$

Check each option:

A) FeSO₄: matches "iron(II) sulfate" — incorrect pairing for "sulfite"
B) Fe₂(SO₃)₃: matches "iron(III) sulfite" — correct
C) FeS: iron sulfide, not sulfite or sulfate — mismatch
D) Fe₂(SO₄)₃: iron(III) sulfate, not sulfite — mismatch
E) Fe₂(SO₄)₃: same as D, mismatch

Conclusion:  The question asks for the incorrect pair, which is A) because it is labeled as sulfate but is actually sulfate, not sulfite, and the question's context suggests the pair's correctness is being tested.

Final answer:  The incorrect pair is A) FeSO₄.