What is the percent composition of hydrogen in water

The remora attaches itself to sharks by means of its mouth. It gets free transportation and protection and also the remnants of

VMariaS [17]

The answer is A. The first option

4 0

2 years ago

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A sample of gas occupies a volume of 73.7 mL. As it expands, it does 133.7 J of work on its surroundings at a constant pressure

katen-ka-za [31]

In thermodynamics, work performed by a system is the energy transferred by the system to its surroundings. It can be calculated by the expression:

W = PdV

Integrating,

We will have,

W = P(V2 - V1)
133.7 (1 litre-atm / 101.325 Joule) ( 760 Torr / atm ) = 783 (V2 - .0737 )
V2 = 1.35 L

Hope this answers the question. Have a nice day.

7 0

3 years ago

How many moles of Cu(OH)2 are soluble in 1L of sodium hydroxide (NaOH) when the pH is 8.23?

Morgarella [4.7K]

Answer:

4.96E-8 moles of Cu(OH)2

Explanation:

Kps es the constant referring to how much a substance can be dissolved in water. Using Kps, it is possible to know the concentration of weak electrolytes. Then, pKps is the minus logarithm of Kps.

Now, we know that sodium hydroxide (NaOH) is a strong electrolyte, who is completely dissolved in water. Therefore the pH depends only on OH concentration originating from NaOH. Let us to figure out how much is that OH concentration.

$pH= -log[H]\\pH= -log (\frac{kw}{[OH]})$

$8.23 = - log(\frac{Kw}{[OH]} \\10^{-8.23} = Kw/[OH]\\ [OH] = Kw/10^{-8.23}$

$[OH]=1.69E-6$

This concentration of OH affects the disociation of Cu(OH)2. Let us see the dissociation reaction:

$Cu(OH)_2 -> Cu^{2+} + 2OH^-$

In the equilibrum, exist a concentration of OH already, that we knew, and it will be added that from dissociation, called "s":

The expression for Kps is:

$Kps= [Cu^{2+}] [OH]^2$

The moles of (CuOH)2 soluble are limitated for the concentration of OH present, according to the next equation.

$Kps= s*(2s+1.69E-6)^2$

"s" is the soluble quantity of Cu(OH)2.

The solution for this third grade equation is $s=4.96E-8 mol/L$

Now, let us calculate the moles in 1 L:

$moles Cu(OH)_2 = 4.96E-8 mol/L * 1 L = 4.96E-8 moles$

7 0

3 years ago

(02.01 MC)

inna [77]

It is likely the neutral atom has 6 protons and 6 electrons; while the negatively charged atom has 7 or more electrons.

The mass of an atom, commonly known as the atomic mass is determined by the number of protons and neutrons as electrons have a very low mass.

This means two atoms can have the same number of protons and neutrons, but a different number of electrons, which would make the atom be charged negatively or positively.

Based on this, if there are two atoms, each with 6 protons but one of these is negatively charged it is because the second atom has 1 or more extra.

Neutral atom:

This atom has 6 protons and an unknown number of neutrons located in the nucleus.
This atom has 6 electrons that orbit the nucleus.
The first energetic level will include 2 electrons while the second energetic level will include the 4 remaining electrons.

Negatively-charged atom:

This atom has 6 protons and an unknown number of neutrons located in the nucleus.
This atom has 7 or even more electrons that orbit the nucleus.
The first energetic level will include 2 electrons while the second energetic level will include up to 8 electrons.

Learn more about atoms in: brainly.com/question/13981855

8 0

2 years ago

Where are calcium ions (Ca2+) stored in the body?

ANTONII [103]

Calcium is stored in bones in the body

5 0

2 years ago

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