How many CL are in a L

What is rate of reaction? Discuss in brief slow and fast reactions.

Sindrei [870]

The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time.

Reactions that happen quickly have a high rate of reaction. For example, the chemical weathering of rocks is a very slow reaction: it has a low rate of reaction. Explosions are very fast reactions: they have a high rate of reaction. Rate of reaction is an example of a compound measure.

3 0

2 years ago

How many moles are in 20g of potassium (K)?

otez555 [7]

Explanation:

Hi for this one u just need to remember and use the equation.

$moles = \frac{mass}{mr}$

then u find mr of potassium which is 39.1.

then u do

$\frac{20}{39.1}$

you get the answer as 0.5115 write ur answer to 3 significant figures which will be 0.512 moles .

hope this helps :)

7 0

2 years ago

1.00 g of a compound is combusted in oxygen and found to give 3.14g of CO2 and 1.29 g of H2O. From these data we can tell thatA.

lora16 [44]

Answer:

the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula

Explanation:

Mass of CO2 obtained = 3.14 g

Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol

The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g

Mass of H2O obtained = 1.29 g

Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol

The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g

% by mass of carbon = 0.857/1 ×100 = 85.7 %

% by mass of hydrogen = 0.0717/1 × 100 = 7.17%

Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %

Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.

5 0

3 years ago

Farmers who raise cotton once used arsenic acid, H₃AsO₄, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with

Stels [109]

Explanation:

The reaction equation will be as follows.

$H_{3}AsO_{4} \rightleftharpoons H_{2}AsO^{-}_{4} + H^{+}$

Hence, the expression for $K_{a}$ is as follows.

$K_{a} = \frac{[H_{2}SO^{-}_{4}][H^{+}]}{[H_{3}AsO_{4}]}$

Let us assume that the concentration of both $[H_{2}AsO^{-}_{4}]$ and $[H^{+}]$ is x.

$2.5 \times 10^{-4} = \frac{x \times x}{0.5}$

x = 0.01118034

This means that the concentration of $[H^{+}]$ is 0.01118034.

Since, we know that the relation between pH and concentration of hydrogen ions is as follows.

pH = $-log [H^{+}]$

= $-log (0.01118034)$

= 1.958

Thus, we can conclude that the pH of a 0.500 M solution of arsenic acid is 1.958.

6 0

3 years ago

The Percentage of salt-water vs. fresh-water:???%

I am Lyosha [343]

Answer:

Over 96 percent is saline. Of total freshwater, over 68 percent is locked up in ice and glaciers. Another 30 percent of freshwater is in the ground.

6 0

2 years ago