chemical changes

Created by

Jaiden Anthony

Cards (46)

What do metals form when they are oxidized?
Metal oxides
What happens to a metal during oxidation?
It loses electrons and gains oxygen
What is reduction in terms of electron transfer?
Gain of electrons and loss of oxygen
What does the reactivity series of metals indicate? 
It orders metals based on their reactivity with acids and water
How do metals react with water according to their position in the reactivity series? 
Only metals above hydrogen will react with water
How does the reactivity of potassium compare to that of iron when reacting with water? 
Potassium reacts more vigorously than iron
What is produced when potassium reacts with water? 
Hydrogen gas and a purple flame
What happens when sodium reacts with water?
Sodium fizzes and melts rapidly to form a ball
How does lithium behave when it reacts with water? 
It fizzes steadily and floats until it disappears
What are the two types of water that metals can react with?
Gaseous water and liquid water
What is the reaction of magnesium with gaseous water?
Magnesium forms magnesium oxide and hydrogen
What is the reaction of sodium with liquid water? 
Sodium forms sodium hydroxide and hydrogen
What do metals above hydrogen produce when reacting with dilute acids? 
A salt and hydrogen gas
Which metals do not react with acids? 
Metals below hydrogen in the reactivity series
What do acids release when dissolved in water? 
Hydrogen ions (H+)
What do alkalis release when dissolved in water? 
Hydroxide ions (OH-)
What does the pH scale measure? 
How acidic or alkaline a substance is
What is formed when acids and alkalis combine? 
Water
What are the three reactions with metallic bases?
Acid + metal oxide = salt + water
Acid + metal hydroxide = salt + water
Acid + metal carbonate = salt + water + carbon dioxide
What are soluble salts? 
Salts that can dissolve in water
How can soluble salts be made? 
By reacting acids with insoluble solids
What is the process of crystallization used for? 
To remove water from soluble salts
To form crystal salts
What are the two ways to measure pH?
Universal indicator (color change)
pH probe (electronic measurement)
What does an increase of 1 pH unit indicate about H+ ion concentration? 
The concentration divides by 10
What is the concentration of H+ ions at pH 0? 
1 mol/dm³
What is the concentration of H+ ions at pH 1? 
0.1 mol/dm³
What is the concentration of H+ ions at pH 2? 
0.01 mol/dm³
What is double neutralization? 
Hydrogen ions (H+) and hydroxide ions (OH-) combine to form water
This process neutralizes each other
What are titrations used for? 
To calculate the volumes of acid and alkali needed in neutralization reactions
What is the balanced symbol equation for the neutralization of hydrochloric acid with sodium hydroxide? 
NaOH + HCl → NaCl + H₂O
What is the relationship between the concentration of NaOH and HCl at neutralization? 
The concentration of HCl is half that of NaOH
How do you calculate the concentration of hydrochloric acid if 10 cm³ of NaOH is needed to neutralize 20 cm³ of HCl? 
The concentration of HCl is 0.05 mol/dm³
What distinguishes strong acids from weak acids? 
Strong acids fully ionize in water (e.g., HCl)
Weak acids do not fully ionize (e.g., CH₃COOH)
What is the process of electrolysis used for? 
To extract metals above carbon in the reactivity series from compounds
What are electrolytes? 
Dissolved ionic compounds that can conduct electricity
Why can solid ionic compounds not conduct electricity? 
Because the ions are not free to move
What happens at the cathode during electrolysis? 
Reduction occurs as positive ions gain electrons
What happens at the anode during electrolysis? 
Oxidation occurs as negative ions lose electrons
What is a disadvantage of electrolysis? 
It is very expensive due to high energy requirements
What are the scenarios for electrolysis? 
Electrolysis of aqueous solutions
Electrolysis of molten compounds