Chemistry: Post your doubts here!

[fahadhameedahmad]

View attachment 62954
someone plz solve these question answer is A

all AS moles questions solved

Moles & Stoichiometry : Past Paper Questions (9701 AS Chemistry MCQs): https://www.youtube.com/playlist?list=PL0U7Zwed3btQLUSSG9QtGUry32Q1D-_xU

 

[fahadhameedahmad]

View attachment 62955
why ans is B plzzzzzzzzzz help

all moles past paper questions solved

Moles & Stoichiometry : Past Paper Questions (9701 AS Chemistry MCQs): https://www.youtube.com/playlist?list=PL0U7Zwed3btQLUSSG9QtGUry32Q1D-_xU

 

[MShaheerUddin]

Help please.

 

[fahadhameedahmad]

View attachment 62954
someone plz solve these question answer is A

 

[fahadhameedahmad]

View attachment 62955
why ans is B plzzzzzzzzzz help

 

[MShaheerUddin]

Sir please answer my one.

 

[Unknown202]

Sir ur video are soo useful but if u can write for each question the year and paper at the title of the video rather than than at the description cuz it takes time to open each and every video to find the question u want plzz sir

 

[fahadhameedahmad]

i will change the format, question number + year in the title
like this

 

[Unknown202]

Yea but if u can also add no.of question not only year and qp plzzzz

 

[fahadhameedahmad]

yes, the question number would be given at the start

 

[corona]

Help please.

The answer is C.

Boron trifluoride is trigonal planar because Boron has 3 valence electrons, while the nitrogen compound is tetrahedral because nitrogen has 5 electrons and only 3 were used for bonding, leaving a pair of unbonded electrons.

The compounds form a coordinate bond after reacting, where both the electrons from the nitrogen atom are used in forming the bond. Hence, the configuration for both sections is tetrahedral.

 

[MShaheerUddin]

 

[MShaheerUddin]

 

[corona]

View attachment 62975

The answer is A.

2Mg(NO3)2 ------> 2MgO + 4NO2 + O2

The ratio of number of moles of NO2 (gas X) and O2 (gas Y) is 4:1

molar masses:
X - 46
Y - 32

mass = (relative) number of moles * molar mass

X - 46*4 = 184
Y - 32*1 = 32

32/184 = 0.174

Hence, the ratio of masses is 1/0.174 (A).

 

[MShaheerUddin]

The answer is A.

2Mg(NO3)2 ------> 2MgO + 4NO2 + O2

The ratio of number of moles of NO2 (gas X) and O2 (gas Y) is 4:1

molar masses:
X - 46
Y - 32

mass = (relative) number of moles * molar mass

X - 46*4 = 184
Y - 32*1 = 32

32/184 = 0.174

Hence, the ratio of masses is 1/0.174 (A).

Bro what this 1 represent in ratio "1"/0.174

 

[MShaheerUddin]

Corona
Bro Can You tell me How can element Calcium have giant structure?

 

[corona]

Bro what this 1 represent in ratio "1"/0.174

The question asks for the ratio of masses of Gas X to Gas Y, but 0.174 is the ratio of masses of Gas Y to Gas X.
Hence, we reciprocate it.

 

[corona]

Corona
Bro Can You tell me How can element Calcium have giant structure?

Metals generally are, on an atomic scale, giant structures in which electrons in the outer shells of the metal atoms are free to move.

Edit:
Reference: https://www.chemguide.co.uk/atoms/structures/metals.html

 

[MShaheerUddin]

OMG Thanks!

 

[MShaheerUddin]