All categories

3 years ago

Why do lighthouses use lenses?

Chemistry

1 answer:

dolphi86 [110]3 years ago

6 0

To see far away? I'm thinking that like human glasses, lighthouses need lenses to see the far away boats. Or humans.

You might be interested in

What is the chemical formula for carbon tetrafluoride?

Degger [83]

The answer is C. CF4

5 0

3 years ago

Read 2 more answers

Consider the following multistep reaction:

chubhunter [2.5K]

The question is incomplete, here is the complete question:

Consider the following multistep reaction:

C+D⇌CD (fast)

CD+D→CD₂ (slow)

CD₂+D→CD₃ (fast)

C+3D→CD₃

Based on this mechanism, determine the rate law for the overall reaction.

Answer: The rate law for the reaction is $\text{Rate}=k'[C][D]^2$

Explanation:

Rate law is the expression which is used to express the rate of the reaction in terms of the molar concentration of reactants where each term is raised to the power their stoichiometric coefficient respectively from a balanced chemical equation.

In a mechanism of the reaction, the slow step in the mechanism determines the rate of the reaction.

For the given chemical reaction:

$C+3D\rightarrow CD_3$

The intermediate reaction of the mechanism follows:

Step 1: $C+D\rightleftharpoons CD;\text{ (fast)}$

Step 2: $CD+D\rightarrow CD_2;\text{(slow)}$

Step 3: $CD_2+D\rightarrow CD_3;\text{(fast)}$

As, step 2 is the slow step. It is the rate determining step

Rate law for the reaction follows:

$\text{Rate}=k[CD][D]$ ......(1)

As, [CD] is not appearing as a reactant in the overall reaction. So, we apply steady state approximation in it.

Applying steady state approximation for CD from step 1, we get:

$K=\frac{[CD]}{[C][D]}$

$[CD]=K[C][D]$

Putting the value of [CD] in equation 1, we get:

$\text{Rate}=k.K[C][D]^2\\\\\text{Rate}=k'[C][D]^2$

Hence, the rate law for the reaction is $\text{Rate}=k'[C][D]^2$

5 0

3 years ago

Which substances can decrease the solubility of CaSO4? how can i identify which substances to use on the solubility table? i sup

natulia [17]

Do not know this answer

4 0

3 years ago

A solid piece of lead has a mass of 23.94g and a volume of 2.10cm^3. from these data, calculate the density of lead in si units

jeyben [28]

A density of a substance is constant. It is an extensive property, meaning it does not depend on the amount of substance because it is a ratio of mass to volume. No matter how much of each there is, they would always have a fixed ratio called density. For lead, the density is

Density = mass/volume
Density = 23.94 g/ 2.10 cm³
Density = 11.4 g/cm³

4 0

3 years ago

5. How many mm are equal to 4.75 x 10-2 m?

liq [111]

Answer:

47.5 mm are equal to 4.75 × 10⁻² m.

Explanation:

Meter and millimeter both are units of length. Millimeter is smaller unit while meter is larger unit. The one meter consist of thousand millimeter or we can say that one thousand millimeters are equal to one meter. In order to convert the meter value into millimeter we have to multiply the values with thousand.

we know that one meter is equal to 1000 millimeter.

1 m = 1000 mm

4.75 × 10⁻² × 1000 = 47.5 mm

47.5 mm are equal to 4.75 × 10⁻² m.

6 0

3 years ago