Advertisements
Advertisements
Question
Answer the following question.
A water sample, which did not give lather with soap, was found to contain \[\ce{Ca(HCO3)2}\] and \[\ce{Mg(HCO3)2}\]. Which chemical will make this water give lather with soap? Explain with the help of chemical reactions.
Advertisements
Solution
- Soap does not lather in hard water due to the presence of the soluble salts of calcium and magnesium in it. So, the given water sample is hard water.
- Hardness of hard water can be removed by the removal of these calcium and magnesium salts.
- Sodium carbonate is used to make hard water soft as it precipitates out the soluble calcium and magnesium salts in hard water as carbonates. Thus, it will make water give lather with soap.
e.g. \[\ce{Ca(HCO3)2_{(aq)} + Na2CO3_{(aq)}->CaCO3_{(s)} + 2NaHCO3_{(aq)}}\]
APPEARS IN
RELATED QUESTIONS
Explain the following.
BeCl2 is covalent while MgCl2 is ionic.
Explain the following.
Lithium floats and water while sodium floats and catches fire when put in water.
Explain the following.
Alkaline earth metals have low values of electronegativity; which decreases down the group.
Write a balanced chemical equation for the following.
\[\ce{CO2}\] is passed into a concentrated solution of NaCl, which is saturated with \[\ce{NH3}\].
Write a balanced chemical equation for the following.
Magnesium is heated in air.
Name the following.
Alkali metal with smallest atom.
Name the following.
The most abundant element in the universe.
When beryllium is ignited in air, the products are ____________.
Which of the following alkaline earth metals has the least affinity towards oxygen?
Which of the following is radioactive?
Which of the following is CORRECT for the atomic and ionic radii of alkali metals?
The diagonal relationship in Be and Al is due to ______.
The oxidation states of O atom in Na2O2 and KO2 are ____________, respectively.
Which of the following is INCORRECT for alkali metals?
Identify the metals having electronic configuration of [Ar]4s2 and [Kr]5s2 respectively.
Which among the following chlorides of alkali metal is deliquescent?
Which among the following elements has highest ionisation enthalpy and bears a diagonal relationship with aluminium?
What is the electronic configuration of third element of group-2 in periodic table?
KO2 (potassium superoxide) is used in oxygen cylinders in space and submarines because it ______.
Which of the following bicarbonates does not exist as a solid?
Which among the following elements of group-2 exhibits anomalous properties?
Which among the group-15 elements does not exist as tetra atomic molecule?
The element of group 2, which forms an amphoteric oxide and a water soluble sulphate is ______.
Which of the following is likely to undergo racemisation during alkaline hydrolysis?
Which of the following trend is correct with respect to the reactivity of alkali metal oxides with water?
