A Solution Is Prepared by Mixing 50

question 38

Multiple Choice

A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO₃) ₂ with 50.0 mL of 0.50 M Co(NO₃) ₂. Sodium hydroxide is added to the mixture. Which hydroxide precipitates first and what concentration of hydroxide ions present in solution will accomplish the separation? K_sp = 2.2 × 10^-20 for Cu(OH) ₂, K_sp = 1.3 × 10^-15 for Co(OH) ₂

• A) Co(OH)₂; [OH^-] = 6.9 × 10^-6 M
• B) Co(OH) ₂; [OH^-] = 2.6 × 10^-7 M
• C) Cu(OH) ₂; [OH^-] = 1.8 × 10^-7 M
• D) Cu(OH) ₂; [OH^-] = 1.1 × 10^-9 M
• E) Cu(OH) ₂; [OH^-] = 1.0 × 10^-17 M

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Definitions:

Common Causes

Sources of variation in a process or system that are inherent and can be attributed to the natural variability of the process.

Run Chart

A graphical representation used in process improvement that displays observed data points in a time sequence, helping identify trends or patterns.

Sample Statistic

A numerical measure that describes some characteristic of a sample of data.

Special Causes

Unusual or non-random factors that cause variation in a process, distinguished from common causes that are inherent to the process.