امتحان لايف Chemistry 22dec | أسئلة الامتحان التجريبي

the number of water molecules are produced from the combination of 1mol of the oxygen with 2mol of hydrogen is:

(A) 4×6.02×10²³

(B) 2×6.02×10²³

(C) 6.02×10²³

(D) 3×6.02×10²³

the world tends to reduce the need for washing machines through production of …….

Ammonia gas combines with hydrogen chloride gas to form white clouds of ammonium according to the equation:

HCl_(g) + NH_3(g) → NH₄Cl_(s)

Given that [Cl=35.5, N=14, H=1]

On the reaction of 34g of ammonia with 18.25g of hydrogen chloride gas, so the remaining mass from reaction is

(A) 25.5_g of NH3

(B) 18.25 _g of HCL

(C) 36.5_g of HCL

(D) 17_g of NH3

the substance is more though if the diameter of its particles is:

(A) 5×10^-2 micro

(B) 5×10^-7 m

(C) 5×10^-9 m

(D) 5×10^-5 mm

the number of molecules present in 16 g of O₂ gas at STP equals the same number of the molecules in:

[Ne=20 , C=12 , O=16 , Ar=36 , Cl=35.5]

(A) 71g of chlorine gas

(B) 22g of CO₂

(C) 20g of neon gas

(D) 40g of argon gas

on the reaction of a solution contains 12.04×10²³ molecule of sodium hydroxide with a quantity of hydrochloric acid, 18g of water was produced according to the following reaction:

NaOH_(aq) + HCL_(aq) → NaCL_(aq) + H₂O_(l)

So the limiting reactant of the reaction is:

(A) HCl

(B) NaCl

(C) NaOH

(D) H₂O

the electric conductivity of carbon molecules is as possible when the size of its molecules is:

(A) 26X10^-5 m

(B) 25X10^-4 m

(C) 14X10^-3

(D) 3X10^-9 m

the opposite graph represents the relation between the number of moles of oxygen and the number of moles of nitrogen on their reaction together

If you have one mole of oxygen reacts with nitrogen and a quantity of oxygen remained without reaction, so the number of nitrogen moles is:

when using an antibiotic that has side effects on healthy cells of the body and chemistry science contributes to solve this problem by using

which of the following graphs represents the correct graphical relation between the volume of electric conductivity:

 the opposite table shows the dimensions of some substances:

Which of the previous dimensions express the nano wires in electronic circuits?

you have two balloons (A and B) the balloon (A) has 0.5 mole of a gas and the balloon (B) has 3.01X10²³ molecule of another gas, so:

the material used as a biological sensor is one dimension of 20mm, the other two dimensions are in nanometers:

(A) 20, 40

(B) 10³, 10⁵

(C) 10^-3, 10^-5

(D) 20, 400