Answer:
See explanation
Explanation:
The calculated concentration of the sodium hydroxide is;
Number of moles= mass/molar mass = 1g/40gmol-1 = 0.025 moles
Concentration= number of moles/volume= 0.025×1000/250 = 0.1 M
This calculated concentration will be different from the molarity of NaOH obtained by standardization with acid. The result will not be more accurate if a different acid is used for the standardization this is because sodium hydroxide is deliquescent and absorbs moisture thereby leading to inaccuracy in the calculated molarity.
Any substance that must be used as a primary standard must not absorb moisture, it must be stable and it must be a substance in its pure form.
Answer:
physical
Explanation:
The zinc (which was already silver) coated the penny. The NaOH dissolved the zinc. (that was what made the water murky) And small pieces of zinc adhered to the penny (coated) It was a physical change because no NEW color was created.
The first one is the second one and the second one is the first one
Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion 
parts by mass of the solution.
L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.
Potassium as it's more reactive than the other two
