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3 years ago

What would be the mass of 4.56x10²³ water molecules

1 answer:

3 0

Every time you see molecules, atoms, & particles think of avagadros #. (6.022 x 10^23)

Answer: 13.6 grams of H2O

Solution: (4.56x10^23) x (1 mol H2O/6.022x10^23) x (18 grams H2O/1 mol H2O) = 13.6 grams of H2O

Using dimensional analysis above makes these types of problems easy.

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Which elements are not balanced in this equation MgO + 2 LiCl = MgCl2 + Li2O

nikitadnepr [17]

B All elements are balanced

8 0

3 years ago

Read 2 more answers

The two naturally occurring isotopes of copper are copper-63 and copper-65. how many neutrons are in one atom of copper-65? 29 3

vampirchik [111]

It's 36. Since copper has 29 protons you do 65-29=36

7 0

4 years ago

Read 2 more answers

In the titration of 50.0 mL of HCl of unknown concentration, the phenolphthalein indicator present in the colorless solution tur

KIM [24]

Answer:

The molarity of HCl is 0.138 M

Explanation:

The titration reaction is as follows:

2HCl + Ca(OH)₂ → CaCl₂ + 2H₂O

When no more HCl is left, the small excess of Ca(OH)₂ added will cause the pH to rise and the indicator will turn. At this point, the number of moles of Ca(OH)₂ added will be the same as half the number of moles of HCl since 1 mol Ca(OH)₂ reacts with 2 moles HCl. Then:

At the endpoint:

moles Ca(OH)₂ = moles HCl / 2

Knowing the number of moles of Ca(OH)₂ added, we can calculate the number of moles of the acid:

mol Ca(OH)₂ = Volume added * concentration of Ca(OH)₂

mol Ca(OH)₂ = 0.0265 l * 0.130 mol/l = 3.45 x 10⁻³ mol Ca(OH)₂

The number of moles of HCl will be:

mol HCl = 2 * 3.45 x 10⁻³ mol = 6.89 x 10⁻³ mol HCl

This number of moles was present in 50.0 ml, then, in 1000 ml:

mol of HCl in 1000 ml = 6.89 x 10⁻³ mol HCl * (1000ml / 50ml) = 0.138 mol

Then:

Molarity HCl = 0.138 M

7 0

4 years ago

57.A cofactor is a(an)

Rudik [331]

A cofactor is an organic or inorganic molecule or ion necessary for proper functioning of some biological catalysts (option E).

<h3>What is a cofactor?</h3>

A cofactor in biochemistry is a molecule that binds to and regulates the activity of a protein.

A cofactor is a metal or coenzyme responsible for the functioning of an enzyme and must be present.

Therefore, a cofactor is an organic or inorganic molecule or ion necessary for proper functioning of some biological catalysts.

Learn more about cofactors at: brainly.com/question/13004767

#SPJ1

3 0

2 years ago

Write electron configurations for Gallium, Ga (Z=31), and show the total valence electrons

ivann1987 [24]

<u>Answer:</u> The electronic configuration of gallium is written below and number of valence electrons is 3.

<u>Explanation:</u>

Electronic configuration is defined as the representation of electrons around the nucleus of an atom.

Number of electrons in an atom is determined by the atomic number of that atom.

Valence electrons are defined as the electrons present in the outermost shell of an atom.

We are given:

An element Gallium having atomic number as 31.

Number of electrons = 31

Electronic configuration of Gallium is: $(Z=31):1s^22s^22p^63s^23p^64s^23d^{10}4p^1$

This element has 3 electrons in its outermost shell. So, the number of valence electrons is 3

Hence, the electronic configuration of gallium is written below and number of valence electrons is 3.

3 0

4 years ago