The arrangement of elements in the Modern periodic table is based on their_______

5. The rate constant for the reaction 3A  4B is 6.00 x 10-3 L•mol-1min-1. How long will it take the concentration of A to drop

valkas [14]

Answer:

it will take 444.44 min to reach 0.25 M from 0.75 M

Explanation:

since the reaction constant is k= 6.00*10⁻³ L*mol⁻¹min⁻¹. For a reaction rate of the form

-dCa/dt=k*Caⁿ

doing a dimensional analysis

[dCa/dt]= mol/(L*min) = [k]*[Caⁿ] = L/(mol*min) * (mol/L)ⁿ

then only n=2 can comply with the dimensional analysis, therefore we get a the second order reaction . Thus

-dCa/dt=k*Ca²

-dCa/Ca² =k*dt

-∫dCa/Ca² =k*∫dt

(1/Ca₂ - 1/Ca₁)= k*Δt

Δt= 1/k*(1/Ca₂ - 1/Ca₁)

replacing values

Δt= 1/k*(1/Ca₂ - 1/Ca₁) = 1/(6.00*10⁻³ L*mol⁻¹min⁻¹)*(1/0.25 M - 1/0.75 M)= 444.44 min

6 0

4 years ago

A 35.0-g piece of copper wire is heated, and the temperature of the wire changes from 29.0°C to 76.0C. The amount of heat absorb

kotykmax [81]

Answer:

0.15cal/g°C

Explanation:

Given parameters:

Mass of copper piece = 35g

Initial temperature = 29°C

Final temperature = 76°C

Amount of heat absorbed = 243cal

Unknown:

Specific heat of copper = ?

Solution:

The specific heat is the amount of heat supplied to a unit mass of substance that causes a 1°C rise in temperature.

Specific heat C, = $\frac{H}{m(T_{2} - T_{1} )}$

where H is the amount of heat supplied

m is the mass of the copper

T is the temperature

Input the parameters;

C = $\frac{243}{35(76 - 29)}$ = 0.15cal/g°C

7 0

3 years ago

Purpose of boiling chip

vichka [17]

Your attempted answer is correct.
Indeed, certain liquids, including water, could superheat when heated in a perfectly smooth container. The superheating could be interrupted by the minutest speck of dust or impurities causing a mass conversion into steam, observed physically as a bumping, causing splashes and endangering operators. Boiling chips introduce these interruptions constantly and ensure a smooth boiling of the liquid.

4 0

3 years ago

________ is a type of root system.

Fiesta28 [93]

Answer: taproot explanation: a taproot is one of the three types of root systems plants have, along with fibrous and adventitious.

5 0

3 years ago

Read 2 more answers

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s) + 3O2 (g) â†’ 2Al2O3 (s) In

jek_recluse [69]

Answer: The percent yield of the reaction is 74 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

$\text{Moles of aluminium}=\frac{2.5g}{27g/mol}=0.092mol$

For oxygen gas:

$\text{Moles of oxygen gas}=\frac{2.5g}{32g/mol}=0.078mol$

The chemical equation for the reaction of titanium and chlorine gas follows:

$4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s)$

By Stoichiometry of the reaction:

4 moles of aluminium reacts with 3 moles of oxygen.

So, 0.092 moles of aluminium reacts with = $\frac{3}{4}\times 0.092=0.069mol$ of oxygen

As, given amount of oxygen is more than the required amount. So, it is considered as an excess reagent.

Thus, aluminium is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

4 moles of aluminium produce = 2 moles of $Al_2O_3$

So, 0.092 moles of aluminium will produce = $\frac{2}{4}\times 0.092=0.046moles$ of $Al_2O_3$

Now, calculating the mass of aluminium oxide:

$\text{Mass of aluminium oxide}=moles\times {\text {molar mas}}=0.046mol\times 102g/mol=4.7g$

To calculate the percentage yield of titanium (IV) chloride, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield = 3.5 g

Theoretical yield = 4.7 g

Putting values in above equation, we get:

$\%\text{ yield of reaction}=\frac{3.5g}{4.7g}\times 100\\\\\% \text{yield of reaction}=74\%$

Hence, the percent yield of the reaction is 74 %

6 0

3 years ago

The arrangement of elements in the Modern periodic table is based on their________