States of Matter
What state of matter has a definite shape and a definite volume?
Solid
What do you call a mixture where you can still see the different parts?
Heterogenous
What type of change produces a new substance: Physical or chemical?
A chemical change.
What happens to the reaction rate when temperature increases?
It increases.
What is the pH range of acids?
Below 7
What state of matter takes the shape of its container but keeps a definite volume?
Liquid.
What is the substance being dissolved in a solution called?
Solute
What is released in an exothermic reaction?
Energy (Heat/light)
What is a catalyst?
a substance that speeds up a reaction without being used up.
What ion do acids release in water?
Hydrogen ions (H^+)
Why can you smell popcorn from across the room even if you cannot see it?
Gas particles spread out and move freely through the air.
What method would you use to recover solid salt from water?
Evaporation
Why is baking a cake a chemical change?
New substances form and it cannot be reversed easily to its original form.
Why does powder react faster than a solid chunk?
more surface area increases collision.
What happens when an acid and a base react?
They form water and a salt (Neutralization).
Dry ice seems to disappear without melting into liquid first. What process is taking place?
Sublimation
Why does stirring help a solute dissolve faster?
It spreads particles out and increases contact with the solvent.
What is the law of conservation of mass?
Mass is neither created nor destroyed in a chemical reaction.
What is collision theory?
Reactions occur when particles collide with enough energy and correct orientation.
Why is ammonia considered a base even though it does not contain hydroxide?
It produces OH^- ions in water.
Why does heating a substance change its state of matter?
Heating increases particle energy, making them move faster and overcome attractions between particles.
Explain why oil and water do not mix using the idea of polarity?
Water is polar and oil is nonpolar, therefore they do not attract and separate into layers.
Explain why breaking bonds and forming bonds are both involved in chemical reactions?
Energy is absorbed to break bonds and released when new bonds form.
Explain how lowering activation energy affects a reaction?
It makes it easier for particles to react, increasing speed.
Explain why a strong acid is more reactive than a weak acid?
Strong acids dissociate completely in water, and fully ionize, producing more H^+ ions.