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JAMB UTME - Chemistry - 2013

Pregunta 1 Informe

What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen?

5 dm 3

20 dm 3

15 dm 3

10 dm 3

Detalles de la respuesta

The volume of carbon dioxide produced by reacting excess carbon with 10 dm^3 of oxygen can be calculated using the balanced chemical equation for the reaction. The balanced chemical equation for the reaction between carbon and oxygen to form carbon dioxide is: C + O2 → CO2 From this equation, it can be seen that one molecule of carbon reacts with one molecule of oxygen to form one molecule of carbon dioxide. So, if we have 10 dm^3 of oxygen, we would need 10 dm^3 of carbon to react with it. The volume of carbon dioxide produced would be equal to the volume of the reactants, which in this case is 10 dm^3 + 10 dm^3 = 20 dm^3. Therefore, the answer is 20 dm^3 of carbon dioxide would be produced.

Lee la nota de la lección en Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Pregunta 12 Informe

The rate of diffusion of a gas Y is twice that of Z If the relative molecular mass of Y is 64 and the two gases diffuse under the same conditions, find the relative molecular mass of Z

32

4

8

16

Detalles de la respuesta

\sqrt{y}

= 2x

\sqrt{Z}

= x

\frac{r z}{r y}

=

\sqrt{\frac{m y}{m z}}

$\frac{2 x}{x}$ = $\sqrt{\frac{64}{m z}}$
$\frac{4}{1}$ = $\frac{64}{m z}$

mz = $\frac{64}{4}$
mz = 16

Lee la nota de la lección en Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Pregunta 18 Informe

10.0 dm3 of water was added to 2.0 mol dm-3 of 2.5dm3 solution of HCl. What is the concentration of the final solution in mol dm-3?

0.4

8.0

2.0

0.5

Detalles de la respuesta

C1V1 = C2V2

C2 = $\frac{C_{1} V_{1}}{V_{2}}$

= $\frac{2.0 \times 2.5}{12.5}$

= 0.4mol/dm-3

Lee la nota de la lección en Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Pregunta 40 Informe

The radioactive emission with the least ionization power is

α−particles

X-rays

γ - r a y s

β−rays

Detalles de la respuesta

The radioactive emission with the least ionization power is gamma (γ) radiation. Gamma radiation is a type of electromagnetic radiation that has the highest frequency and shortest wavelength among all types of radiation. While it is highly penetrating and can cause damage to biological tissues, it has the least ionization power because it carries no electric charge and does not interact strongly with matter. This means that gamma radiation can easily pass through materials without being deflected or slowed down, and it takes a lot of energy to ionize atoms or molecules through gamma radiation. In comparison, alpha and beta radiation are particles that carry an electric charge and interact more strongly with matter, making them more ionizing than gamma radiation.

Lee la nota de la lección en Structure Of The Atom (WAEC)

Lee la nota de la lección en Periodic Chemistry (Nigeria Only) (WAEC)

Structure Of The Atom

Periodic Chemistry (Nigeria Only)

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