How would you expect the boiling point of methane to compare with the boiling point of water?
The boiling points would probably be different, because products and reactants usually have different properties.
It is impossible to tell, because chemical reactions don't give us any clues about the properties of products
compared to reactants.
The boiling points would probably be the same, because products and reactants always have the same properties
9 answers
The boiling points of methane and water would be different.
Connie and Dewayne know that solid potassium reacts very strongly with water, producing a chemical called potassium hydroxide along with hydrogen gas. They know the chemical equation looks like this.
2K + 2H20 -> 2KOH + some amount of H2
a. There are 4 atoms of hydrogen shown on the reactant side. How many total atoms of hydrogen must be on the product side?
(1 point)
• 2
• 4
• 6
• 8
2K + 2H20 -> 2KOH + some amount of H2
a. There are 4 atoms of hydrogen shown on the reactant side. How many total atoms of hydrogen must be on the product side?
(1 point)
• 2
• 4
• 6
• 8
The total number of atoms of hydrogen on the product side would be 4 atoms.
b. What does the law of conservation of matter (or the law of conservation of mass) tell the students? (1 point)
• Matter is never gained or lost in a chemical or physical process
• Matter is always gained or lost in a chemical or physical process
• Matter might be gained in a chemical or physical process.
• Matter might be lost in a chemical or physical process.
• Matter is never gained or lost in a chemical or physical process
• Matter is always gained or lost in a chemical or physical process
• Matter might be gained in a chemical or physical process.
• Matter might be lost in a chemical or physical process.
The law of conservation of matter (or mass) tells the students that matter is never gained or lost in a chemical or physical process.
c. Connie and Dewayne combine 78 grams of potassium with 36 grams of water.
What would they expect the total mass of the products to be? Why?
• the total mass of the products would be greater than 114 grams, because water is really heavy.
• The total mass of the products would be 114 grams, because mass cannot be gained or lost in the process.
• The total mass of the products would equal 78 grams, because the mass of water doesn't
make a difference.
• the mass burned into nothing, would be something less than 14 grams, because some of the mass is burned into nothing
What would they expect the total mass of the products to be? Why?
• the total mass of the products would be greater than 114 grams, because water is really heavy.
• The total mass of the products would be 114 grams, because mass cannot be gained or lost in the process.
• The total mass of the products would equal 78 grams, because the mass of water doesn't
make a difference.
• the mass burned into nothing, would be something less than 14 grams, because some of the mass is burned into nothing
The total mass of the products would be 114 grams because mass cannot be gained or lost in the process according to the law of conservation of matter.
b. What gives you a good clue that chemical reactions are used to convert natural resources into synthetic products?
•the properties of synthetic materials and the natural resources used to make them are different
•The properties of synthetic materials and the natural resources used to make them are the same.
• It's impossible to compare and contrast the properties of synthetic and natural materials.
• Synthetic materials and natural resources don't have any properties.
•the properties of synthetic materials and the natural resources used to make them are different
•The properties of synthetic materials and the natural resources used to make them are the same.
• It's impossible to compare and contrast the properties of synthetic and natural materials.
• Synthetic materials and natural resources don't have any properties.
The clue that chemical reactions are used to convert natural resources into synthetic products is that the properties of synthetic materials and the natural resources used to make them are different.
1 answer