Answer is: the ratio of amount NaOH reacting per unit amount FeCl₃ is 3 mol NaOH /1 mol FeCl₃.
Balanced chemical reaction:
3NaOH(aq) + FeCl₃(aq) → 3NaCl(aq) + Fe(OH)₃(s).
NaOH is sodium hydroxide.
FeCl₃ is iron(III) chloride.
Coefficient for sodium hydroxide is three and for iron(III hydroxide is one.
I believe it has something to do with the H2O molecules, because a chemical compound is not a mixture.
Answer:

Explanation:
1 mole of any substance contains the same number of particles. The particles can vary (atoms, molecules, formula units), but there are always 6.022*10²³ particles. In this case, the particles are formula units of potassium nitrate or KNO₃.
Let's create a ratio.

Since we are trying to find the formula units in 0.250 moles, we multiply by that number.

The units of moles of potassium nitrate cancel.

The denominator of 1 can be ignored, so we can make a simple multiplication problem.


If we round to the nearest tenth, the 0 in the hundredth place tells us to leave the 5 in the tenth place.

0.250 moles of potassium nitrate is approximately equal to 1.5*10²³ formula units of potassium nitrate and choice B is correct.
Answer:
The function of the respiratory system is to move two gases: oxygen and carbon dioxide. Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them.
Answer:
The correct option is: provide a source of counterions to prevent the build-up of charge at both the cathode to the anode.
Explanation:
A salt bridge is a U-shaped glass tube that is used in a voltaic cell or galvanic cell to connect the oxidation and reduction half-cells and complete the electric circuit.
<em>It allows the ions to pass through it, thus preventing the accumulation of charge on the anode and cathode as the chemical reaction proceeds.</em>
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Therefore, the correct option is: <u>provide a source of counterions to prevent the build-up of charge at both the cathode to the anode.</u>