Aqueous solution of borax above 62°C gives crystals of________________?

A. Na2b4o7.4h2o
B. Na2b4o7.5h2o
C. Na2b4o7.2h2o
D. Na2b4o7.10h2o

Which of the following is not a use of silicon ?

A. Lubricants
B. Hydraulic brakes
C. Antifreeze
D. Water repellent

CO2 is gas while SiO2 is solid at room temperature?

A. Carbon is non-metal while silicon is semi-metal
B. Co2 is an independent molecule while sio2 has network covalent structure
C. Co2 forms multiple bond while silicon does not form multiple bonds
D. Silicon has all sigma bonds

Identify the correct statement regarding CO_______________?

A. It combines with h2o to form carbonic acid
B. It reacts with red blood cells of haemoglobin
C. It is powerful oxidizing agent
D. It is used to prepare aerated drinks

Boric acid cannot be used__________________?

A. As antiseptic in medicine
B. For washing eyes
C. In soda bottles
D. For enamel and glazes

Which element can form tripositive ion ?

A. Beryllium
B. Carbon
C. Silicon
D. Aluminium

Which of the following is metasilicic acid ?

A. H2sno3
B. H2sio3
C. H3aso4
D. H3sbo4

Boron in soil has been considered micronutrient for_________________?

A. Soil porocity
B. Proper growth of plants
C. Alkalinity of soil
D. All

Substance which is found in dried up lakes of Tibet and California is_______________?

A. Tincal
B. Boric acid
C. Calcium carbonate
D. Colemanite

Which of the following does not give Borax bead test ?

A. Cu
B. Cr
C. Ni
D. A1