Question

Which is true about Rochelle’s salt and lead zirconate?
A. Rochelle’s salt is ferroelectric while lead zirconate is anti-ferroelectric
B. Rochelle’s salt is anti-ferroelectric and lead zirconate is ferroelectric
C. Both are ferroelectric
D. Both are anti-ferroelectric

Answer 1

The substance properties or characteristics should be matched either they are ferroelectric or anti-ferroelectric. The ferroelectric substance or materials have spontaneity for the electric polarization and which can be reversed by electric field. In anti-ferroelectric materials or substances they are ordered in a type of array having adjacent dipoles.

Complete answer:
Potassium sodium tartrate tetrahydrate is double salt of tartaric acid which is prepared by La Rochelle. This is the first material which is discovered to exhibit piezoelectricity. It is used in electroplating, in electronics and piezoelectricity. It is also used as an ingredient in Fehling’s solution like a reagent for reducing sugars. Also used as a combustion accelerator in cigarette paper which are quite similar to an oxidizer in pyrotechnics. It is a common precipitant in protein crystallography and also used as an ingredient in the Biuret reagent which is mainly used for measuring protein concentration
So we have to check for two materials that are Rochelle’s salt and lead zirconate that whether they both are ferroelectric and antiferroelectric or both are different in the cases of ferroelectric or anti-ferroelectric.
First we will see Rochelle’s salt. It is a potassium sodium tartrate tetrahydrate that is $KNa{C_4}{H_4}O.4{H_2}O$. It belongs to the family of uniaxial ferroelectrics.
Now about lead zirconate. Its chemical formula is $PbZr{O_3}$. It is an anti ferroelectric material which has a melting point of about 12507 degree Celsius. It has a curie temperature of 230 degree Celsius.

Additional Information:
Lead zirconate also known as lead zirconium titanate. It is a ceramic material that shows piezoelectric effects. Piezoelectric effect means that compounds get changed or change their shape whenever an electric field is applied on the compound. It exhibits greater sensitivity and higher operating temperature. It is used in a number of various applications. For example ultrasonic transducers and piezoelectric resonators. It is also used in manufacture or making of ceramic resonators.

Note: Rochelle’s salt are basically of ferroelectric material and lead zirconate are of anti-ferroelectric material. Both these substances or compounds use or show the same effect that is piezoelectric effect. Piezoelectric effect means that compounds get changed or change their shape whenever an electric field is applied on the compound.