By using the formula, mass = density x volume, we
calculate mass in grams
20.0 mL CH₃COOH x (1.05 g / mL) = 21.0
g CH₃COOH
To find the moles, molar mass of CH₃COOH = 60.05g/mol<span>
21.0 g </span>CH₃COOH x (1 mole CH₃COOH / 60.05 g CH₃COOH)
= 0.350 moles CH₃COOH
To find molarity,<span>
[</span>CH₃COOH] = moles CH₃COOH / L of solution = 0.350 /
1.40 = 0.250 M CH₃COOH<span>
When </span>CH₃COOH is dissolved in water, it produces
small and equal amounts of H₃O⁺+ and C₂H₃O₂⁻.
<span>
Molarity , </span>CH₃COOH<span> + H</span>₂O <==> H₃O⁺ + C₂H₃O₂⁻
<span>
<span>Initial 0.250 0 0 </span>
Change -x x x
Equilibrium 0.250-x x x
K</span>ₐ = [H₃O⁺][C₂H₃O₂⁻] / [HC₂H₃O₂] = (x)(x) /
(0.250-x) = 1.8 x 10⁻⁵
<span>Since K</span>ₐ is relatively small, we can neglect the -x
term after 0.250 to simplify
<span>x</span>² / 0.250 = 1.8 x 10⁻⁵
x² = 4.5 x 10⁻⁶
<span>
x = 2.1 x 10</span>⁻³<span> = [H</span>₃O⁺]
pH = -log [H₃O⁺] = -log (2.1 x 10⁻³) = 2.68
Answer
If the temperature is increased , the number of collision per second increases.
Explanation
Temperature is proportional to the average kinetic energy of a sample of a gas according to the equation PV=n R T. An increased in temperature , increases the kinetic energy of the gas particles which in turn rises the velocity of the gas particles hitting the walls of the container. The more the number of particles the higher the collision rate and greater the pressure as long as the volume of container and the temperature are constant.
To determine how many protons are present, simply know or use the following equation
X = number of protons
Y = number of electrons
Z = formal charge of the element
X - Y = Z = 0 for a neutral atom
X - Y = 2
Then to solve for x
X = Y + 2.
This means that we would need an additional 2 more protons than electrons.
Answer:
1.51 x 10²⁴atoms
Explanation:
Given parameters:
Number of moles of Cr = 2.50mol
Solution;
what is a mole;
a mole of any substance is the amount of substance that contains the avogadro's number of particles which is 6.02 x 10²³ particles
The particles here can be atoms, protons, neutrons, electrons e.t.c
1 mole contains 6.02 x 10²³ atoms
2.5 moles will contain 2.5 x 6.02 x 10²³ = 1.51 x 10²⁴atoms
