Textbook Question
Name the following ions: (a) Ba2+ (b) Cs+ (c) V3+ (d) HCO3- (e) NH4 (f) Ni2+ (g) NO2- (h) ClO2- i) Mn2+ (j) ClO4-
Ch.2 - Atoms, Molecules & Ions
Chapter 2, Problem 159
What are the charges on the positive ions in the following compounds? (a) Zn(CN)2 (b) Fe(NO2)3 (c) Ti(SO4)2 (d) Sn3(PO4)2 (e) Hg2S (f) MnO2 (g) KIO (h) Cu(CH3CO2)2
Verified step by step guidance1
Step 1: Identify the overall charge of the compound. Since these are neutral compounds, the sum of the charges of the positive and negative ions must equal zero.
Step 2: Determine the charge of the negative ion (anion) in each compound. Use the known charges of common polyatomic ions and monatomic ions. For example, CN^- has a charge of -1, NO2^- has a charge of -1, SO4^2- has a charge of -2, PO4^3- has a charge of -3, S^2- has a charge of -2, O^2- has a charge of -2, IO^- has a charge of -1, and CH3CO2^- has a charge of -1.
Step 3: Calculate the total negative charge in each compound by multiplying the charge of the anion by the number of anions present in the formula. For example, in Zn(CN)2, there are 2 CN^- ions, so the total negative charge is 2(-1) = -2.
Step 4: Determine the charge on the positive ion (cation) by ensuring the total positive charge balances the total negative charge to make the compound neutral. For example, in Zn(CN)2, the total negative charge is -2, so the charge on Zn must be +2 to balance it.
Step 5: Repeat the process for each compound, ensuring the sum of the charges of the cations and anions equals zero for each compound.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Oxidation States
Oxidation states, or oxidation numbers, indicate the degree of oxidation of an atom in a compound. They help in determining the charge of ions in ionic compounds. For example, in Zn(CN)2, zinc typically has an oxidation state of +2, which is essential for identifying the charge of the positive ion.
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02:42
Oxidation Numbers
Polyatomic Ions
Polyatomic ions are charged entities composed of two or more atoms covalently bonded, which function as a single ion. Understanding common polyatomic ions, such as sulfate (SO4^2-) or nitrate (NO3^-), is crucial for determining the overall charge balance in compounds like Fe(NO2)3 and Ti(SO4)2.
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01:20Polyatomic Ion Variations
Ionic Compounds
Ionic compounds consist of positively charged cations and negatively charged anions. The overall charge of the compound must be neutral, which means the total positive charge from cations must equal the total negative charge from anions. This principle is key to deducing the charges on the positive ions in compounds like Sn3(PO4)2 and Cu(CH3CO2)2.
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Related Practice
Textbook Question
What are the formulas of the compounds formed from the following ions? (a) Ca2+ and Br- (b) Ca2+ and SO42- (c) Al3+ and SO42-
Textbook Question
Ammonia (NH3) and hydrazine (N2H4) are both compounds of nitrogen and hydrogen. Based on the law of multiple pro-portions, how many grams of hydrogen would you expect 2.34 g of nitrogen to combine with to yield ammonia? To yield hydrazine?
Textbook Question
Prior to 1961, the atomic mass unit (amu) was defined as 1/16 the mass of the atomic weight of oxygen; that is, the atomic weight of oxygen was defined as exactly 16. What was the mass of a 12C atom prior to 1961 if the atomic weight of oxygen on today's scale is 15.9994?
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