Which among the following compound, nitrogen shows the oxidation state of +5?
N has +5 in HNO3. Oxidation state of O is -2 and H is +1.
Which among the following forms basic oxide?
As we move down the group metallic character increases so Bi is a metal thus its oxide is basic.
In laboratory ammonia is prepared by heating
2(NH4Cl) + Ca(OH)2 → (CaCl)2 + 2(NH3) + 2(H2O)
Hence C is correct.
Ammonia has a higher boiling point and is less volatile because of
NH3 undergo intermolecular hydrogen bonding and therefore it has higher boiling point compared to other hydrides of group 15.
Which compound is used as the cooling liquid in refrigerators?
NH3 is used as cooling liquid in refrigerators.
At what temperature white phosphorous changes to red phosphorous?
White phosphorus when heated to 300° C polymerization occurs and it changes to Red Phosphorus.
is the structure of
H3PO2 is Hypophosphorus acid
Elements of which group are known as ore forming elements?
Maximum ores are of group 16 elemnts (O, S etc).
Most metal oxides are
Metal oxides are basic and ionic in nature.
The stability of hydrides of group 16 elements decreases in the order
As we move down the group bond length increases therefore stability of hydrides decreases. Order of bond length O-H < S-H < Se-H < Te-H.
Formula of oleum is
Oleum is H2S2O7
Which among the following does not exhibit positive oxidation state?
Fluorine is most electronegative element therefore can only gain electrons. Thus it only shows negative oxidation state.
Which of the following is the strongest Lewis base?
Correct Answer :- D
Explanation : Lewis bases need to be able to donate electrons. Fluorine is the most electronegative element in the halogens followed by chlorine, bromine and iodine.
Due to fluorine being strongly electronegative, it draws the electron density towards itself which makes it difficult for nitrogen atom to donate its lone pair of electrons. So, NF is the least basic. This trend follows the strength of electronegativity of the halides.
Since iodine is least electronegative, it is the most basic trihalide of nitrogen.
So, we have the trend, in decreasing order of basic strength:
NF3 < NCl3 < NBr3 < NI3
Hydrogen sulphide reacts with lead acetate forming a black compound which reacts with hydrogen peroxide to form another compound. The colour of the compound is
PbS + H2O2 → PbSo4(white) + H2O
Which of the following is thermally the most stable?
Stability of hydrides decreases down the group so most stable is H2O
Which of the following is prepared by cyanamide process?
CaNCN + 3H2O → CaCO3 + 2NH3
Ozone can be detected by using
Ozone is detected by using Hg.
Which of the following oxides reacts with both HCl and NaOH?
ZnO is an amphroteric oxide.
Name the gas whose formula was established by Sorret?
Sorret established formula of ozone.
Which colour is given by CuSO4 with ammonia?
Cu2+ + 4NH3 → [Cu (NH3)4]2+ (blue)
CN = 0.5(V+M-C+A) For XeF2 CN = 5 so shape will be linear and structure will be trigonal pyramidal.
A metal X on heating in nitrogen gas gives Y. Y on treatment with water gives a colourless gas which when passed through copper sulphate solution gives a blue colour. Y is
Mg3N2 reacts with water to evolve NH3. Which reacts with copper ion to form blue color complex.
The reagent used to distinguish between H2O2 and O3 is:
H2O2 can decolorize the color of KMnO4
When chlorine is passed through concentrated hot solution of KOH, the compound formed is
Cl2 on treatment with conc. Base form ClO3-
Ammonia can be dried using
CaO is used to dry NH3