If the density of methanol is 0.793 kg L–1, what is its volume needed for making 2.5 L of its 0.25 M solution?
Let the volume of 0.25 M of ethanol needed = x Molar mass of methanol (CH3OH) = (1 × 12) + (4 × 1) + (1 × 16) = 32 g mol–1 = 0.032 kg mol–1
Molarity of methanol solution
= 24.78 mol L–1 (Since density is mass per unit volume)
Applying, M1V1 = M2V2
(Given solution) (Solution to be prepared)
(24.78 mol L–1) x = (2.5 L) (0.25 mol L–1)
x = 0.0252 L
x = 25.22 mL
The mass of an electron is 9.1 × 10–31 kg. If its K.E. is 3.0 × 10–25 J, calculate its wavelength.
Calculate the amount of carbon dioxide that could be produced when
(i) 1 mole of carbon is burnt in air.
(ii) 1 mole of carbon is burnt in 16 g of dioxygen.
(iii) 2 moles of carbon are burnt in 16 g of dioxygen.
Calculate the wavelength of an electron moving with a velocity of 2.05 × 107 ms–1.
Balance the following redox reactions by ion – electron method :
(a) MnO4 – (aq) + I – (aq) → MnO2 (s) + I2(s) (in basic medium)
(b) MnO4 – (aq) + SO2 (g) → Mn2+ (aq) + HSO4– (aq) (in acidic solution)
(c) H2O2 (aq) + Fe 2+ (aq) → Fe3+ (aq) + H2O (l) (in acidic solution)
(d) Cr2O7 2– + SO2(g) → Cr3+ (aq) + SO42– (aq) (in acidic solution)
In a process, 701 J of heat is absorbed by a system and 394 J ofwork is done by the system. What is the change in internal energy for the process?
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
In a reaction A + B2 → AB2 Identify the limiting reagent, if any, in the following reaction mixtures.
(i) 300 atoms of A + 200 molecules of B
(ii) 2 mol A + 3 mol B
(iii) 100 atoms of A + 100 molecules of B
(iv) 5 mol A + 2.5 mol B
(v) 2.5 mol A + 5 mol B
At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?
Which one of the following will have largest number of atoms?
(i) 1 g Au (s)
(ii) 1 g Na (s)
(iii) 1 g Li (s)
(iv) 1 g of Cl2(g)
Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure. What will be its density at STP?
What will be the mass of one 12C atom in g?
ΔU0of combustion of methane is – X kJ mol–1. The value of ΔH0 is
(i) = ΔU0
(ii) > ΔU0
(iii) < ΔU0
(iv) = 0
What are pesticides and herbicides? Explain giving examples.
Write the significance/applications of dipole moment.
The equilibrium constant for a reaction is 10. What will be the value of ΔG0 ? R = 8.314 JK–1 mol–1, T = 300 K.
Describe the structure of the common form of ice.
Explain the important aspects of resonance with reference to the ion.
What are electron deficient compounds? Are BCl3 and SiCl4 electron deficient species? Explain.
A mixture of 1.57 mol of N2, 1.92 mol of H2 and 8.13 mol of NH3 is introduced into a 20 L reaction vessel at 500 K. At this temperature, the equilibrium constant, Kc for the reaction N2 (g) + 3H2 (g) ↔ 2NH3 (g) is 1.7 × 102.
Is the reaction mixture at equilibrium? If not, what is the direction of the net reaction?
Describe the change in hybridisation (if any) of the Al atom in the following reaction.
Not clearly explain step by step
no i dont like it
In the first step u wrote ethanol ð
Thanks
Thanks a lot
Great solution
Can u please explain how you get the molarity