4) After reacting hydrochloric acid with sodium hydroxide, the temperature has increased from 21˚C to 52˚C. This reaction is:
Exothermic
True & false Dissolving potassium nitrate is exothermic process
True
Which gas is always produced when a metal reacts with water?
Oxygen
Carbon Dioxide
Hydrogen
Carbon Monoxide
……………….. doesn’t react with Acid.
Copper
Iron
Potassium
Sodium
1- Which statement best describes an exothermic reaction?
A reaction that releases heat to its surroundings
A reaction that does not involve energy
a) A reaction that only happens in cold conditions
A reaction that absorbs heat from its surroundings
Which metal reacts vigorously with water and oxygen?
Copper
Silver
Potassium
Gold
What happens when zinc is attached to a steel ship?
Zinc reacts slower than iron
Zinc prevents rust by reacting first
Zinc makes the ship heavier
Zinc increases corrosion
Which of the following metals is the most reactive?
Copper
Iron
Gold
Potassium
Which of the following is an example of an endothermic reaction?
Explosion of fireworks
Ice melting into water
Burning wood
A candle flame giving off heat
True or False Zinc is sacrificed to protect iron in steel ships.
True
………From the poisonous metals that dissolved in Rio Tinto River
Cadmium
Zinc
Uranium
Strontium
Which metal is described as inert in the document?
Iron
Gold
Magnesium
Zinc
……………………….. process releases heat energy to the surroundings
Freezing
Which of the following is NOT an inert metal?
Platinum
Iron
Rhodium
Palladium
True & false The flare includes strontium nitrate, which makes a red flame.
True
Copper is valuable because it is:
Magnetic and soluble
Hard and easily corroded
Malleable and unreactive
Brittle and reactive
Iron filings burn in air to make ………………
Iron oxide
True or False Copper reacts easily with oxygen and water.
False
Which term describes a substance that does not take part in chemical reactions?
Reactive
Corrosive
Conductive
Inert
In the reactivity series, metals become ______ as you go down the list.
Heavier
More magnetic
More reactive
Less reactive
Which of the following represents sodium peroxide formula
NaO
Na2O
NaO2
Na2O2
True or False Helium is an inert non-metal element.
True
True or False The reactivity series lists metals in order of how readily they react.
True
True & false The anomalous value shows us that our values are precise.
false
True or False Gold is more reactive than copper.
False
Which metal is used for sacrificial protection on steel ships?
Silver
Zinc
Gold
Copper
3) A grade 7 student wants to know if the reaction of hydrochloric acid and sodium hydroxide solution is exothermic or endothermic. He did an experiment for this reaction. Give the name of this reaction:
Neutralization
True or False Magnesium is more reactive than zinc.
True
True or False Inert substances take part in chemical reactions.
False
From metal elements common physical properties is
Dull
Insulators
Shiny
Liquids
Iron reacts with water and oxygen to form Rust which is
Hydrated iron oxide
Rust oxide
Iron oxide
Iron sulfate
Which non-metal is inert?
Neon
Sulfur
Oxygen
Carbon
Which of these metals is less reactive than magnesium?
Zinc
Calcium
Sodium
Copper
Some metals react with oxygen to make ……...
Sulfates
Nitrates
Oxides
Salts
The pH of the Rio Tinto River in spin is ….
2
6
7
13
Which property makes copper suitable for cooking pans?
It is a poor conductor of heat
It reacts with acids
It rusts easily
It is a good conductor of heat
Endothermic changes transfer energy from the surroundings
True
A) Why is an endothermic reaction useful in a cold pack? Explain how it helps when someone has an injury.
- When ammonium nitrate dissolves, it absorbs heat energy from its surroundings, making the cold pack cool. - This cooling helps reduce pain and swelling by ta
True & false The Rio Tinto River is red because iron compounds are dissolved in it.
True
True or False Reactivity decreases from bottom to top of the series.
False
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