the electronic configuration of a particular neutral atom is 1s²2s²2p63s²3p². what is the number of unpaired electrons in this atom
3 is the answer p has 3 orbitals meaning 3 blanks. Each blank has 2 electrons, up and down. The... View Article
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how much energy will you get from one gram of glucose
Glucose has a caloric value of four calories per gram. Glucose is the primary component of all carbohydrates.
how many gram of ice at –10ºc is needed to cool 100 g of water from 25ºc to 10ºc?
Mass of water = 100g Latent heat of fusion of ice = 80 Specific heat of ice = 0.5 Q(hot... View Article
100ml of 0.1 M NaOH is added to 100 ml of a 0.2 M CH3COOH solution. The pH of resulting solution will be (pka=4.74)
NaOH + CH3COOH ⟶ CH3COONa + H2O Now it is a buffer pH = pka + log[salt/acid] pH = 4.74... View Article
if rate constant of a first order reaction is 2.31 × 10–3 s–1 and initial concentration of the reactant is 1.6 m then the rate of the reaction after second half life period will be
t1/2 = 0.693/k = 0.693/2.31×10−3 =300s
In the case of a zero-order reaction, the ratio of time required for 75% completion to 50 % completion is
Its a Zero Order Reaction, Time required for 75% completiont1 = (100−25)/2k = 75/2kt2 = (100−50)/2k = 50/2kRatio of times... View Article
assertion( a) the water molecule has a bent or v- shape reason (r) since two of the tetrahedral positions are occupied by lone pairs, water molecule has a bent or v- shape
Both Assertion and Reason are valid, and Assertion is explained correctly by Reason. Water molecules display a bent form. In... View Article
van der waals constant (a) for the gases a, b, c and d are 1.25, 3.29, 4.28 and 0.244 respectively. the gas which is most easily liquefied is
Van der Waals forces are weak electric forces that attract neutral molecules in gases, liquefied and solidified gases, and practically... View Article
number of sp3 carbon atoms, pi bonds and sigma bonds in enol form of acetophenone respectively
In acetophenone, only one sp3 hybridised carbon is present. Acetophenone is an organic chemical with the formula C6H5C(O)CH3 and the... View Article
the equilibrium constant (k) for the reaction 2hi(g) ⇌ h2(g) i2(g) at room temperature is 5.7 and that of 698 k is 2.8 x 10-2. this implies that the forward reaction is
With the increase in temperature, K value decreases, which. means that at high temperature the reaction proceeds in a backward... View Article
The vapour pressure of a liqid solution containing A and B is 99 torr. Colvulate mole % of in vapour phese
P = PA + XB (PB-PA)99 = 100 + XB (80-100)99 = 100 – 20XB20 XB = 1XB = 1/20YB... View Article
Mole fraction of the component A in vapour phase is x1 and mole fraction of component A in liquid mixture is x2
pA=p∘Aχ2, vapour pressure of A. Mole fraction of A in vapour = pA/ptotal χ1 = p∘Aχ2/p ptotal = p∘Aχ2/χ1
An organic compound gave the following results C=53.3%,H=15.6,N=31.1%, mol. wt =45. What is molecular formula of the compound?
Element % No. of Moles Simple Ratio C=53.3 53.3/12=4.44 4.44/2.22=2 H=15.6 15.6/1=15.6 15.6/2.22=7 N=31.1 31.1/14=2.22 2.22/2.22=1 Hence, empirical formula = C2H7N... View Article
carbon monoxide gas is dissolved in water at 25⁰c and 0.01 atm . henry’s law constant is 5.8 × 10⁴ atm . the mole fraction of co is
The mole fraction of a gas in solution is related to partial pressure of the gas above the solution by... View Article
The bond length (pm) of F2, H2, Cl2 and I2, respectively is
The bond length is proportional to the atomic size, and vice versa.The atomic size of hydrogen is the smallest. As... View Article
if 1 mol ideal gas expanded from 5 l to 50 l at 27°c then entropy change involved in the process will be
ΔS = 2.303 nR log(V2/V1)ΔS = 2.303 x 1 x 8.314 log(50/5) ΔS = 2.303 x 1 x 8.314 log(10)... View Article
if enthalpy of combustion of c(s), h2(g) and ch4(g) are –x, – y and –z kj mol–1 then enthalpy of formation of ch4(g) is
ΔH1 = −890kJ/molΔH2 = −393.5kJ/molΔH3 = 2×(−285.8)kJ/molC + 2H2 ⟶ CH4ΔHf = (−393.5)+890.3+2(−285.8)=−74kJ/mol
ph of an aqueous solution of 0.1 m nh4cl solution is (given pkb (nh4oh) = 4.7)
Given concentration of NH4Cl = 0.1M pKb = 4.7 Formula = pH = -1/2 log Kw – 1/2 log C... View Article
borax bead test is used to identify the nature of cation present in solution by observing the colour of bead. the colour and bead of copper formed during its borax bead test in hot oxidising flame is
Boric anhydride is a non-flammable substance. When it reacts with a coloured metallic salt, it produces a distinctive coloured metal... View Article
0.1 mol of ideal gas compressed reversibly isothermally from 10 l to 1 l at 100 k. the work done in the process is
It is a reversible & isothermal process. n = 0.1 molP1 = 1P2 = 10T = 100 Work done =... View Article
