A student is asked to prepare 400.0 mL of a 0.25M HCl solution. The students find a bottle labeled ""2.0M HCl."" How many mL of the 2.0M solution are needed to prepare the 0.25M solution?

The answer to your question is He needs 50 ml of 2.0 M HCl.

Explanation:

Data

Volume 2 = 400 ml

[HCl] 2 = 0.25 M

[HCl] 1 = 2.0 M

Volume 1 = ?

To solve this problem use the dilution formula

Formula

                     V₁C₁  =  V₂C₂

Solve for V₁

                     V₁ = V₂C₂ / C₁

Substitution

                      V₁ = (400)(0.25) / 2

Simplification

                      V₁ = 100 / 2

Result

                      V₁ = 50 ml

question: ray weighs 100 kilograms, his wrestling partner, bobby, weighs 50 kilograms. if ray moves at 4 m s , how fast will bobby have to run at him to apply an equal amount of kinetic energy?

answer: 8 m/s he needs to run twice as fast to keep up so he has some work to do

explanation:   if the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

question answered by

(jacemorris04)

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.