The half-life of a certain element is 100 days. How many half-lives will it be before only one-eighth of this element remains?

Write molecular, complete ionic, and net ionic equations for the reactions that occur, if any, when solutions of the following s

Stells [14]

<span>Ca(NO3)2 (aq) + Na2SO4 (aq) --> CaSO4 (s) + 2NaNO3 (aq) Ca2+ (aq) + 2NO3- (aq) + 2 Na+ (aq) + SO4 (aq) --> CaSO4 (s) + 2Na+ (aq) + 2NO3- (aq) cancel out spectator ions Ca2+ (aq) + SO4 (aq) ---> CaSO4 (s hope it helps</span>

5 0

3 years ago

Which event is most likely an example of a chemical reaction

Inessa [10]

Explanation:

One example of a chemical reaction is the rusting of a steel garbage can. That rusting happens because the iron (Fe) in the metal combines with oxygen (O2) in the atmosphere. Chemical bonds are created and destroyed to finally make iron oxide (Fe2O3).

7 0

3 years ago

Rank the following salts in order of decreasing pH of their 0.1 M aqueous solutions.(a) FeCl2, FeCl3, MgCl2, KClO2 .(b) NH4Br, N

Firlakuza [10]

Answer:

a) FeCl2, FeCl3, MgCl2, KClO2.

KClO2 --> K+ + ClO2-; ClO2- will hydrolyse to form HClO +OH-

Mg+2, Fe+2 and Fe+3 ions will form acidic solutions, since theyfom slightly amount of

Mg+2 + 2H2O <-> Mg(OH)2 + 2H+

Fe+2 + 2H2O <-> Fe(OH)2 + 2H+

Fe+3 + 3H2O <-> Fe(OH)3 + 3H+

Therefore;

decreasing pH is high pH to low pH:

KClO2 > MgCl2 > FeCl2 > FeCl3

b) NH4Br, NaBrO2, NaBr, NaClO2.

NH4Br is acidic, forms NH4+ and NH4+ dnates H+ to form NH3 andH+

NaBrO2 is basic, forms Na+ + BrO2- then H2O + BrO2- HBrO2

NABr is neutral, NaClO2 is basics, forms Na+ + ClO2-then H2O + ClO2- HClO2

decreasig pH:

NaClO2 > NaBrO2 > NaBr >NH4Br

Note that HClO2 is stronger acid than HBrO2, therefore, expectmore HBrO2 formation

NaBrO2 > NaClO2 > NaBr >NH4Br

5 0

3 years ago

What is the difference between a crystalline material and an amorphous material? Give an example of each type.

Igoryamba

Answer :

As we know that there are two types of solids.

(1) Amorphous Solids

(2) Crystalline Solids

Amorphous Solids : It is a type of solids in which the constituent particles of the matter are arranged in the random manner.

That means there is no proper arrangement of atoms in solid lattice but the atoms or molecules are closely spaced that means they can move freely from one place to another.

The examples of amorphous solid are, plastics, glass, rubber, metallic glass, polymers, gel, fused silica, pitch tar, thin film lubricants, wax.

Crystalline Solids : It is a type of solids where the constituent particles of the matter are arranged in the specific manner.

That means there is a proper arrangement of atoms in solid lattice. They do not have space between the molecules or atoms and they can not move freely from one place to another.

The examples of crystalline solids are, quartz, calcite, sugar, mica, diamonds, snowflakes, rock, calcium fluoride, silicon dioxide, alum.

7 0

3 years ago

Enter a balanced equation for the complete combustion of liquid C3H7OH. Express your answer as a chemical equation. Identify all

Vlad1618 [11]

2 C₃H₇OH (l) + 9 O₂ (g) → 6 CO₂ (g) + 8 H₂O (g)

Explanation:

To balance the chemical equation the number of atoms of each element entering the reaction have to be equal to the number of atoms of each element leaving the reaction, in order to conserve the mass.

Bellow we have the balanced chemical equation of the complete combustion of C₃H₇OH:

C₃H₇OH (l) + (9/2) O₂ (g) → 3 CO₂ (g) + 4 H₂O (g)

to have integer coefficients we multiply the reaction with 2:

2 C₃H₇OH (l) + 9 O₂ (g) → 6 CO₂ (g) + 8 H₂O (g)

where:

(l) - liquid

(g) - gaseous

Learn more about:

combustion reaction

brainly.com/question/9425444

balancing chemical equations

brainly.com/question/13941483

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7 0

3 years ago