An alloy consists of rubidium and one of the other alkali metals. A sample of `4.6g` of the alloy when allowed to react with water, liberates `2.241dm^(3)` of hydrogen at `STP`.
Relative atomic masses: `A_(T)(Li)=7,A_(T)(Na)=23,A_(T)(K)=39,A_(T)(Rb)=85.5,A_(T)(Cs)=1.33`
Which alkali metal is the component of the alloy?
An alloy consists of rubidium and one of the other alkali metals. A sample of `4.6g` of the alloy when allowed to react with water, liberates `2.241dm^(3)` of hydrogen at `STP`.
Relative atomic masses: `A_(T)(Li)=7,A_(T)(Na)=23,A_(T)(K)=39,A_(T)(Rb)=85.5,A_(T)(Cs)=1.33`
Which alkali metal is the component of the alloy?
Relative atomic masses: `A_(T)(Li)=7,A_(T)(Na)=23,A_(T)(K)=39,A_(T)(Rb)=85.5,A_(T)(Cs)=1.33`
Which alkali metal is the component of the alloy?
Text Solution
Verified by Experts
The correct Answer is:
`M-alkali metal
Reaction:`2M+2H_(2)Orarr2MOH+H_(2)`
`n(H_(2)):0.1`mol
`n(M):0.2`mol
Mean molar mass:
`M=(4.6g)/(0.2mol)=23gmol^(-1)`
Reaction:`2M+2H_(2)Orarr2MOH+H_(2)`
`n(H_(2)):0.1`mol
`n(M):0.2`mol
Mean molar mass:
`M=(4.6g)/(0.2mol)=23gmol^(-1)`
|
Topper's Solved these Questions
Similar Questions
Explore conceptually related problems
An alloy consists of rubidium and one of the other alkali metals. A sample of 4.6g of the alloy when allowed to react with water, liberates 2.241dm^(3) of hydrogen at STP . Relative atomic masses: A_(T)(Li)=7,A_(T)(Na)=23,A_(T)(K)=39,A_(T)(Rb)=85.5,A_(T)(Cs)=1.33 What composition in % by mass has the alloy?
An experimenter is inside a uniformly accelerated train. Train is moving horizontally with constant acceleration a_(0) . He places a wooden plank AB in horizontal position with end A pointing towards the engine of the train. A block is released at end A of the plank and it reaches end B in time t_(1) . The same plank is placed at an inclination of 45^(@) to the horizontal. When the block is released at A it now climbs to B in time t_(2) . It was found that (t_(2))/(t_(1))= 2^((5)/(4)) . What is the coefficient of friction between the block and the plank?
Knowledge Check
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. Which of the follwing is/are correct for cyanide process of extraction of gold?
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. Which of the follwing is/are correct for cyanide process of extraction of gold?
A
Sodium cynaide is sweet in taste and is also used in making chocolates
B
Sodium cyanide if escapes into ground water then it produces hydrogen cyanide which is toxic to many animals.
C
It is an example of pyrometallurgy.
D
It is an example of leaching process
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. Which of the follwing is/are correct for cyanide process of extraction of gold?
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. Which of the follwing is/are correct for cyanide process of extraction of gold?
A
Sodium cynaide is sweet in taste and is also used in making chocolates
B
Sodium cyanide if escapes into ground water then it produces hydrogen cyanide which is toxic to many animals.
C
It is an example of pyrometallurgy.
D
It is an example of leaching process
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. The correct ionic reaction for the process is//are:
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. The correct ionic reaction for the process is//are:
A
`Au+2CN^(-)rarrAr[(CN)_(2)]^(-)`
B
`Zn+2CN^(-)rarZn[(CN)_(2)]^(-)`
C
`4Au+8CN^(-)+2H_(2)O+O_(2)("air")rarr4[Au(CN)_(2)]^(-)("soluble")+4OH^(-)`
D
`Zn+4CN^(-)rarrZn[(CN)_(4)]^(2-)`
Similar Questions
Explore conceptually related problems
a. If the velocity of a body is zero, does it mean that its acceleration is also zero ? (Yes//No) b. If the acceleration of a body is zero does it mean that its velocity is also zero ? (Yes//No) c. If a body travels with uniform acceleration a_(1) for a time t_(2) thenthe average acceleration is given by a_(av) =(a_(1)t_(1)+a_(2)t_(2))/(t_(1)+t_(2) (Yes//No) d. If a body starts from rest and moves with uniform acceleration the displacemects of the body is 1 s , 2 s, 3 s , etc., are in the ration of (1: 4: 9), etc. (True//False) e. For a body moving whith uniform acceleration, the displacent of the bosy in successive seconds is in the ration of 1: 3: 5: 7 .........................(True//False) .
Answer the following: a. Which of the following has density greater than water ? Li, Na, K, Cs . b. Arrange K, Li, Rb in other of increasing electrode potential. c. Arrange Na, Li, K and Cs in increasing order of metallic bond. d. Which among Na, K, Cs and Li forms stable hydride ? e. On reacting eith oxygen, potassium can form K_(2)O , KO_(2) and K_(2)O_(2) . Is it correct ? f. Give the name of the hardest alakli metal. g. Arrange the following in order orf increasing polarising albility. Li^(o+), Na^(o+), K^(o+), Cs^(o+) h. Mention some of the properties of alkali metals which increse down the group. i. Mention some of the properties of alkali metals which decrease down the group.
A classical model for the hydrogen atom consists of a singal electron of mass m_(e) in circular motion of radius r around the nucleous (proton). Since the electron is accelerated, the atom continuously radiates electromagnetic waves. The total power P radiated by the atom is given by P = P_(0)//r^(4) where P_(0) = (epsi^(6))/(96pi^(3)epsi_(0)^(3)c^(3)m_(epsi)^(2)) (c = velocity of light) (i) Find the total energy of the atom. (ii) Calculate an expression for the radius r(t) as a function of time. Assume that at t = 0 , the radiys is r_(0) = 10^(-10)m . (iii) Hence or otherwise find the time t_(0) when the atom collapses in a classical model of the hydrogen atom. Take: [2/(sqrt(3))(e^(2))/(4piepsi_(0))1/(m_(epsi)c^(2)) = r_(e) ~~ 3 xx 10^(-15) m]
The colour in the coordination compounds can be readily explained in terms of crystal field theory. Consider, for example, the complex [Ti(H_(2)O)_(6)]^(3+) , which is violet in colour. This is an octahedral complex where the single electron [ Ti^(3+) is a 3d^(1) system] in the metal d-orbital is in the t_(2g) level in the ground state of the complex. The next higher state available for the electron is the empty e_(g) level. If light corresponding to the energy of blue-green region is absorbed by the complex, it would excite the electron from t_(2g) level to the e_(g) level (t_(2g)^(1)e_(g)^(0)to t_(2g)^(0)e_(g)^(1)) . Consequently, the complex appears violet in colour. The crystal field theory attributes the colour of the coordination compounds to d-d transition of the electron. It is important to note that in the absence of ligand, crystal field splitting does not occur and hence the substance in colourless. For example, removal of water from [Ti(H_(2)O)_(6)]Cl_(3) on heating renders it colourless. Similarly, anhydrous CuSO_(4) is white, but CuSO_(4).5H_(2)O is blue in colour. Out of the t_(2g) and e_(g) d-orbitals, which has a higher energy?
Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t [Au(CN)_(2)]^(-) , which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to [Zn(CN)_(4)]^(2-) , Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. The correct ionic reaction for the process is//are: