Skip to main content
Ch.4 - Chemical Quantities & Aqueous Reactions
Tro - Chemistry: A Molecular Approach 4th Edition
Tro4th EditionChemistry: A Molecular ApproachISBN: 9780134112831Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoTro 4th EditionCh.4 - Chemical Quantities & Aqueous ReactionsProblema 113
Capitolo 4, Problema 113

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. A solution is 0.050 M in calcium chloride and 0.085 M in magnesium nitrate. What mass of sodium phosphate would you add to 1.5 L of this solution to completely eliminate the hard water ions? Assume complete reaction.

Guida verificata passo dopo passo
1
Identify the chemical reactions involved: \( \text{Ca}^{2+} + \text{PO}_4^{3-} \rightarrow \text{Ca}_3(\text{PO}_4)_2 \) and \( \text{Mg}^{2+} + \text{PO}_4^{3-} \rightarrow \text{Mg}_3(\text{PO}_4)_2 \).
Calculate the moles of \( \text{Ca}^{2+} \) in the solution: \( 0.050 \text{ M} \times 1.5 \text{ L} \).
Calculate the moles of \( \text{Mg}^{2+} \) in the solution: \( 0.085 \text{ M} \times 1.5 \text{ L} \).
Determine the moles of \( \text{PO}_4^{3-} \) needed to react with both \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) using stoichiometry from the balanced equations.
Calculate the mass of \( \text{Na}_3\text{PO}_4 \) required using the moles of \( \text{PO}_4^{3-} \) and the molar mass of \( \text{Na}_3\text{PO}_4 \).

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Hard Water Composition

Hard water is characterized by the presence of dissolved minerals, primarily calcium (Ca²⁺) and magnesium (Mg²⁺) ions. These ions can form insoluble compounds with certain anions, leading to the formation of scale in pipes and appliances. Understanding the concentration of these ions is crucial for determining how to treat hard water effectively.
Video consigliato:
Percorso guidato
04:19
Matter Composition

Precipitation Reactions

A precipitation reaction occurs when two soluble salts react to form an insoluble product, or precipitate. In this case, phosphates react with calcium and magnesium ions to form insoluble calcium phosphate and magnesium phosphate. This concept is essential for calculating the amount of sodium phosphate needed to remove hard water ions from the solution.
Video consigliato:
Percorso guidato
01:53
Selective Precipitation

Stoichiometry

Stoichiometry involves the calculation of reactants and products in chemical reactions based on balanced equations. It allows us to determine the exact amounts of substances needed for a complete reaction. In this scenario, stoichiometry is used to calculate the mass of sodium phosphate required to react with the given concentrations of calcium and magnesium ions in the solution.
Video consigliato:
Percorso guidato
01:16
Stoichiometry Concept
Pratica correlata
Domanda del libro di testo

A solution contains Cr3+ ions and Mg2+ ions. The addition of 1.00 L of 1.51 M NaF solution causes the complete precipitation of these ions as CrF3(s) and MgF2(s). The total mass of the precipitate is 49.6 g. Find the mass of Cr3+ in the original solution.

2318
views
Domanda del libro di testo

Find the mass of barium metal (in grams) that must react with O2 to produce enough barium oxide to prepare 1.0 L of a 0.10 M solution of OH-.

1366
views
Domanda del libro di testo

Predict the products and write a balanced molecular equation for each reaction. If no reaction occurs, write 'NO REACTION.' c. liquid pentanol (C5H12O) and gaseous oxygen

938
views
Domanda del libro di testo

An acid solution is 0.100 M in HCl and 0.200 M in H2SO4. What volume of a 0.150 M KOH solution would completely neutralize all the acid in 500.0 mL of this solution?

2414
views
Domanda del libro di testo

Predict the products and write a balanced molecular equation for each reaction. If no reaction occurs, write 'NO REACTION.' b. Cr(NO3)3(aq) + LiOH(aq) →

1424
views