CHEMISTRY THE P-BLOCK ELEMENTS-11th
QUIZ-19
Dear Readers,
IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies.
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..
Q1.Global warming is called
Solution
Green-house effect.
Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect.
Green-house effect.
Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect.
Q2.Select the correct statement
Solution
Silicon dioxide(silica) is a network solid with tetrahedral coordination and is a giant molecule.
Silica has a three-dimensional network structure. In silica, silicon is sp3-hybridized and is thus linked to four oxygen atoms and each oxygen atom is linked to two silicon atoms forming a three-dimensional giant molecule. This three-dimensional network structure imparts stability to SiO2 crystal and hence a large amount of energy is required to break the crystal resulting in high melting point.
Silicon dioxide(silica) is a network solid with tetrahedral coordination and is a giant molecule.
Silica has a three-dimensional network structure. In silica, silicon is sp3-hybridized and is thus linked to four oxygen atoms and each oxygen atom is linked to two silicon atoms forming a three-dimensional giant molecule. This three-dimensional network structure imparts stability to SiO2 crystal and hence a large amount of energy is required to break the crystal resulting in high melting point.
Q3.Element of group 14 used in semiconductors are
Solution
Si,Ge
Silicon is found in the basis of all electronic devices. It is a semiconductor.
Germanium is another element used in semiconductors.
Ultra pure form of Ge and Si are used to make translators and semi conductors.
Si,Ge
Silicon is found in the basis of all electronic devices. It is a semiconductor.
Germanium is another element used in semiconductors.
Ultra pure form of Ge and Si are used to make translators and semi conductors.
Q4.Which of the following oxides of nitrogen is paramagnetic?
Solution
NO2
NO2 is paramagnetic due to the presence of unpaired electron on the nitrogen atom.
NO2
NO2 is paramagnetic due to the presence of unpaired electron on the nitrogen atom.
Q5.Which is/are correct statements about P4O6 and P4O10
Solution
P4O6 + H2O → H3PO3 (ON of +3 in both)
P4O10 + H2O → H3PO4 (ON of +5 in both)
P4O6 + H2O → H3PO3 (ON of +3 in both)
P4O10 + H2O → H3PO4 (ON of +5 in both)
Q6.The major constituent in cement is
Solution
Calcium carbonate is the major constituent in cement
Calcium carbonate is the major constituent in cement
Q7.In the preparation of red phosphorus from white phosphorus
Solution
A little iodine is used as catalyst.
In the preparation of red phosphorus from white phosphorus I2 is used as catalyst at 2500C
A little iodine is used as catalyst.
In the preparation of red phosphorus from white phosphorus I2 is used as catalyst at 2500C
Q8.Methanides are
Solution
Methanides H2O → CH4
Be2C H2O → CH4
Al4C3 H2O → CH4
Methanides H2O → CH4
Be2C H2O → CH4
Al4C3 H2O → CH4
Q9.The type of hybridization of boron in diborane is
Solution
sp3−hybridisation
Diborane, B2H6 has two electrons each, three centred bonds.
Each Boron atom (B) is linked with four hydrogen atoms. This makes tetrahedral geometry. Hence, each Boron atom is sp3−hybridised.
Hence, boron in diborane is sp3−hybridised.
sp3−hybridisation
Diborane, B2H6 has two electrons each, three centred bonds.
Each Boron atom (B) is linked with four hydrogen atoms. This makes tetrahedral geometry. Hence, each Boron atom is sp3−hybridised.
Hence, boron in diborane is sp3−hybridised.
Q10. Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite
Solution
Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds.
Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds.
