Reactants Products

SOLID NICKEL

SULFURIC ACID

solution

NICKEL (III) SULFATE

solution

HYDROGEN GAS

2 Ni (s) 3 H2SO4 (aq) Ni2(SO4)3 (aq) 3 H2(g)

What kind of particles?

Atoms

Ions ions

(atoms in ) molecules

# protons in each _28___

# electrons in each _28__

net charge __0__

H+ ion

_1_ protons

_0_electrons

_+1_ net chg

SO42-

ion composed of

sulfur and

oxygen atoms bonded together by

covalent bonds

with net charge of -2

Ni3+

ion

___28__protons

__25__electrons

__+3__net chg

SO42-

ion Draw it with S in middle.

H atom

_1_ protons

_1_electrons

_0_ net chg

H atom

_1_ protons

_1_electrons

_0_ net chg

Arrangement

Atoms held in fixed

positions - solid

Ions dissociated in solution

(split up) – free to move

and surrounded by water

molecules

Ions dissociated in solution

(split up) – free to move and

surrounded by water molecules

Hydrogen molecules are

widely spaced and free to

move in the gas

Attractions

Metallic bonds –

loose free moving

sea of electrons

shared by all the

atoms

Ion-dipole attractions –

the positive hydrogen ions

are attracted to negative

end of the water molecules

and the negative sulfate

ions are attracted to the

positive hydrogen end of

water molecules

Ion-dipole attractions – the

positive nickel ions are

attracted to negative end of the

water molecules and the

negative sulfate ions are

attracted to the positive

hydrogen end of water

molecules

Nonpolar covalent bonds hold the hydrogen atoms

together in the hydrogen

molecules.

These nonpolar molecules

have no oppositely charged

ends so they are not attracted

to each other and stay far

apart. Weak induced dipole-

induced dipole attractions act between the hydrogen

molecules.

Ionic Equations

Ni(s) + H+(aq) + SO4

2-(aq)

Ni 3+

(aq) + SO42-

(aq) + H2 (g)

Ni(s) + H+(aq) Ni

3+ (aq) + H2 (g)

Help for the ionic equations

From the molecular equation to the ionic equation

2 Ni (s) 3 H2SO4 (aq) Ni2(SO4)3 (aq) 3 H2(g)

The only change is splitting up the ions that are in solution.

So if it is not in solution (aq) – leave it the same and

if it is in solution and IONS - split them up.

Do NOT include the subscripts (little numbers) unless they are part of the polyatomic ion.

Example – sulfate ion is four oxygen atoms and one sulfur atom so you must include the four SO42-

Do show the charge on the ion.

Lab 5 Worksheet Name _________________________________ period ___ A nickel is added to sulfuric acid. A single replacement reaction occurs. Nickel (III) sulfate forms. Bubbles

form and rise to the surface. When the bubbles stop forming, the nickel is much smaller than before.

1. Complete the analysis on the back before proceeding.

Use the ionic equations

Ni(s) + H+(aq) + SO4

2-(aq) Ni

3+ (aq) + SO4

2-(aq) + H2 (g)

2. What happened to the nickel. Write a half-reaction.

Write down the nickel before and after from the ionic equation.

Ask yourself – atom, ion, or molecule

Ask yourself – how many protons? How many electrons?

Then look – what changed?

Ni(s) Ni 3+

(aq) + 3e- atom ion

28 p 28 p

28e- 25 e- lost three electrons -- OXIDIZED 0 +3

3. What happened to the hydrogen. Write a half-reaction.

Write down the hydrogen before and after from the ionic equation.

Ask yourself – atom, ion, or molecule

Ask yourself – how many protons? How many electrons?

Then look – what changed?

H+(aq) H2 (g)

ion molecule (atoms in)

1 p 1p 1p (two H atoms)

0 e- 1 e- 1 e- (sharing a pair of electrons)

+1 ` 0 0

Gained electrons --- REDUCED

4. What happened to the sulfate?

NOTHING - it was an ion in solution attracted to water molecules

and it still is an ion in solutions attracted water molecules. 5. Based upon the description of the reaction, why did the reaction stop? How do you know?

Since there is still nickel left after the bubbling stops, we must have leftover nickel.

We must have run out of sulfuric acid, so that is why the reaction stopped.

Sulfuric acid is the LIMITING REACTANT – it limits how much hydrogen gas you can make.

6. Is the remaining solution still acidic? Explain.

No, we ran out of acid.

The mass of nickel was 5.061 grams and 25 mL of 2.0 M H2SO4 solution was used.

7. How many moles of nickel are present initially?.

Ask yourself – what are we looking for? Put it at the right.

Ask yourself – what is the starting info closest to what I am looking for?

Write it at the left.

Then look – what factors of one (top equals bottom) can I use to turn the starting point into the ending

point?

5.0161 g Ni 1 mole Ni Moles Ni

58.71 g Ni

What are we looking for? Put it at the right.

what is the starting info

closest to what I am looking for?

8. How many moles of sulfuric acid are present initially?

9. If all the nickel reacts, how many moles of hydrogen gas can be produced?

10. If all the sulfuric acid reacts, how many moles of hydrogen gas can be produced?

After the reaction, the remaining nickel was removed from solution. The nickel was rinsed over the beaker

and the solution was decanted. The solution was heated to dryness. The mass of nickel removed from the

solution was 3.042 grams. The mass of the dried nickel sulfate solid was 13.084 g.

12. Calculate the mass of nickel that actually reacted.

13. Use the mass of nickel that actually reacted to calculate the mass of nickel (III) sulfate that should have

been produced.

14. Why was the leftover nickel rinsed over the beaker.

15. Why was the mass of the remaining nickel measured?

16. Why was the remaining solution dried?

ANALYSIS OF THE REACTION OF ALUMINUM IN HYDROCHLORIC ACID

THE CHANGES

ALUMINUM

ALUMINUM before ALUMINUM after Notes-

What kind of particle?

What kind of particle?

What happened to the aluminum?

How many protons?

How many protons?

How many electrons?

How many electrons?

net charge?

net charge?

Chemistry term for this change

half reaction

CHLORINE

CHLORINE before CHLORINE after Notes-

What kind of particle?

What kind of particle?

What happened to the aluminum?

How many protons?

How many protons?

How many electrons?

How many electrons?

net charge?

net charge?

Chemistry term for this change

HYDROGEN IONS

HYDROGEN before HYDROGEN after Notes-

What kind of particle?

What kind of particle?

What happened to the hydrogen?

How many protons?

How many protons?

How many electrons?

How many electrons?

net charge?

net charge?

Chemistry term for this change

half reaction

SINGLE REPLACEMENT REACTIONS.