Chemistry

No, Iron is a homogeneous mixture as long as the iron is pure

No elements are made up of a compound. I think you mean 'Which elements make up iron oxide?', and the answer to that is iron and oxygen.

iron and sulphur

The symbol of the cation of FeCl2 is Fe2+. A cation is a positively charged ion and to find the formula of any compound you must balance the cations with the anions.

LiBr is a neutraliy charged ionic molecule

The cation is lithium and its symbol is ' Li^(+) '.

The anion is bromide and its symbol is ' Br^(-) '.

Hydrochloric Acid and Calcium chloride does NOT react, because of the 'common ion' effect ( chloride).

Acid ; Hydrochloric Acid

Metal ; Zinc.

Word eq'n

Hydrochloric Acid + Zinc = Zinc Chloride + Hydrogen

Balanced reaction eq'n.

2HCl(aq) +Zn(s) = ZnCl2(aq) + H2(g)

'HCL' is NOT a recognised formula.

If you mean ' HCl ' Note the lower case 'l'. , then it does NOT appear on the Periodic Table.

Reason; it is a compound and not an element.

As a compound it is a combination of two elements, viz., hydrogen (H) and chlorine (Cl). Both these elements DO appear on the Periodic Table.

NB ; The Periodic Table is a LIST of ELEMENTS , Not compounds.

NNB When writing the symbols of chemical elements. Single letter symbols are ALWAYS a CAPITAL letter. A double letter symbol is , first letter is a CAPITAL letter, and the second letter is lower case.

Hence hydrogen is 'H'.

Chlorine is 'Cl ' , NOT ;CL'.

The single capital letter 'L' as a symbol does NOT exist in the Periodic Table.

Reflection of light from a mirror is a physical change, not a chemical change.

It is a physical process because no new substance is formed and the mirror’s chemical composition remains unchanged. The light simply changes its direction when it strikes the mirror.

An account is typically suspended when payment remains unpaid for 61 days or more, leading to a delinquent status under standard account terms.

'ni' means nothing as it is NOT on the Periodic Table.

If you mean ' Ni '., then it is Nickel.

NB On the Periodic Table. Single letter elemental symbols are ALWAYS a capital LETTER. Double letter symbolss are ; first letter is a CAPITAL letter and the second letter is lower case. .

This is the recognised international standard, and is done to avoid confusion.

So Nickel is ' Ni ' NOT 'ni'.

C stands for carbon. It belongs to group-14

NO!!!! Because if it was , when there is a lightning strike we would all be 'burnt to a cinder'. Lightning is an electrical discharge, which will ignite flammable material.

Yes!!!

Air contains oxygen. It is the oxygen which supports combustion. Oxygen of itself does NOT combust, but supports combustion.

None!!!!

What is ' h2o2 '???

If you mean ' H2O2' (Hydrogen Peroxide)/ Then there are 4 atoms/

Two hydrogen atoms and two oxygen atoms.

The structure is ' H-O-O-H '.

NB In chemical elemental symbols , Single letter symbols are ALWAYS a CAPITAL letter. This is the IUPAC/International recognised standard, and as shown in the Periodic Table.

Hence hydrogen is 'H' , NOT 'h' , and oxygen is 'O' , NOT 'o'.

Remember the mathematical equation.

moles = mass(grams) / Relative molecular/atomic mass).

Shortened to

mol = mass(g) / Mr

For relative molecular/atomic mass refer to the Periodic Table.

Mr of Water (H2O)

There are two hydrogen atoms and one oxygen atom.

So from the Periodic Table the Atomic mass of an hydrogen atom is '1'

There being two hydrogen atoms , then 1 x 2 = 2

Similarly for oxygen. The atomic mass of oxygen is '16'

There being one oxygen atom , then 1 x 16 =16

Since the one molecule contains the three atoms, then add the numbers 2 + 16 = 18 ( Relative Molecular Mass (Mr) of Water0.

Hemce if you have 36 grams of water.

Then

moles(H2O) = 36g /18

moles(H2O) = 2 moles.

This method is good for any substance.

NB

Other moles Equations.

Moles = [conc] X vol/mL / 1000 ( liquids)

Moles = pressure X volume / ( Gas Constant X Temperature) (Gases).

NNB These three moles equations are algebraically interchangeable.

Nitrogen and oxygen.

The atmosphere ( air) is composed of a mixture of gases . viz.,

Nitrogen ; 79 %

Oxygen ; 20 %

The remaining 1% contains, water ,carbon dioxide, noble gases, sulphur dioxide, nitrogen dioxide, methane, hydrogen sulphide. They are are all in tiny quantities.

Valency is '2'

Formula is ' ^(-)O(O=)C-C(=O)O^(-)

NB it is similar to Ethanoic(Acetic) Acid, but has an acid functional group at each end.

When water reacts with alcohol, particularly in the case of mixing, they form a homogeneous solution due to their ability to hydrogen bond with each other. This interaction can lead to changes in physical properties, such as boiling point and viscosity. However, there is no chemical reaction that occurs in the typical sense, as both substances retain their molecular identities in the mixture. In some cases, such as with certain alcohols and under specific conditions, the formation of azeotropes may occur, which can affect distillation processes.

Write down the Balanced Reaction Eq;n

Zn + 2HCl = ZnCl2 + H2

We note the molar ratios are all 1:1 :: 1:1

That is one mole zince produces one mole hydrogen.

So calculate the moles of zinc.

mol(Zn) = 5g / 65.4(Atomic mass)

mole(Zn) = 0.0764 moles. ; Equivalent to one mole above.

Hence

mole(H2) = 0.0764 moles ; Also Equivalent to one mole above.

NB one mole of any gas occupies 24 litres ( 24000 cm^(3)).

Hence 0.0765 moles X 24000 = 1834 cm^(3) = 1.834 litre.s

What law????

If you mean the Law of Conservation of Mass'.

Chemical reaction eq'ns MUST be balanced. otherwise mass is NOT conserved.

Solid/liquid reaction easily satisfy the law.

However if a gas is involved, it is difficult to measure mass. However, you can collect the volume of gas , and thereby convert to mass. to satisfy the Law of Conservation of Mass'.

Water is a compound. It does NOT share nitrogen.

Water has the chemical formula ' H2O '. This means it has two atoms of hydrogen and one atom of oxygen. It does NEITHER contain NOR share with nitrogen.

Water, salt water, and oxygen are pure substances because they consist of only one type of molecule. Tea is a mixture of different substances, including water and various phytochemicals. Copper and brass are chemical compounds made up of multiple elements, making them impure substances. Air is a mixture of gases, with nitrogen and oxygen being the main components.

Yes, a compound with the chemical formula C15H30 would be a member of the alkane series. Alkanes have the general formula CnH2n+2, where n represents the number of carbon atoms in the alkane molecule. In this case, n=7, so the compound falls into the alkane series.

An ALK**Y**NES

Structurally, ' R - C///C - R'