New answers tagged

1 vote

What happens to the hydroxide ion concentration when you add caustic soda to ammonia?

The general equation set approach: There are often less standard situations, like this with $\ce{NaOH}$ addition, without handy equations to be used. In such a case, a generally applicable approach ...
  • 29.8k
2 votes

Are acids effective in removing soap scum?

The white deposits may be limescale or soap scum, or a combination of both. Is there a high level of hardness in the water in your area? Therefore, one cannot generalize that acidic cleaners are ...
  • 33.7k
1 vote

What happens to the hydroxide ion concentration when you add caustic soda to ammonia?

The initial system contains $0.0038$ mol $\ce{OH-}$ (and $\ce{NH4^+}$) and $0.1962$ mol $\ce{NH3}$. Adding $0.02$ mol $\ce{NaOH}$ will consume $y$ mol of $\ce{NH4^+}$ and of $\ce{OH-}$ and produce the ...
  • 22.5k
4 votes

Are acids effective in removing soap scum?

Soap is a combination of a metal (e.g. sodium) and a fatty acid (e.g., palmitic acid). If you use acid to break the metal off (e.g., $\ce{CH3(CH2)14COONa + HCl -> CH3(CH2)14COOH + Na Cl}$) you're ...
2 votes

How do you calculate the pH of 0.01 M H2S solution (hydrogen sulfide, an amphiprotic acid)?

$\ce{H2S}$ is not an amphiprotic acid, it is a diprotic acid (meaning it can donate two protons rather than one). You could say e.g. dihydrogen phosphate is an amphiprotic acid because it can either ...
  • 32.7k
1 vote

Why do electrochemical sensors need reference electrodes

In other words, you propose replacing the reference electrode with its own solution with a logistically simpler "copper vs test solution" electrode. Your copper electrode potential will ...
  • 750
2 votes
Accepted

Why do electrochemical sensors need reference electrodes

Consider the case where you wish to remember a friend's address with a reference to a famous restaurant, but the restaurant magically keeps shifting its position without warning day by day! This would ...
  • 33.7k
5 votes
Accepted

How does pH affect the rate that CaCO3 dissolves in freshwater?

Calcium carbonate dissolves by falling apart into ions (calcium cations and carbonate anions): $$\ce{CaCO3(s) <=> Ca^2+(aq) + CO3^2-(aq)}$$ The rate of dissolution does not depend on pH. However,...
  • 32.7k

Top 50 recent answers are included