chapte 4 Flashcards
(29 cards)
What is the difference between a physical change and a chemical change?
A physical change alters the physical state of a substance without changing its composition, while a chemical change converts one substance into another.
What are the two main processes involved in a chemical reaction?
Breaking bonds in the reactants and forming new bonds in the products.
How are reactants and products represented in a chemical equation?
Reactants are written on the left, and products are written on the right. Coefficients show the number of molecules that react or are formed.
What does the law of conservation of mass state about chemical reactions?
Atoms cannot be created or destroyed in a chemical reaction.
Q: Why is it important to balance a chemical equation?
A: To ensure the same number of atoms of each element on both sides of the equation, maintaining the law of conservation of mass.
Q: What are the steps to balance the chemical equation for the reaction of propane with oxygen?
- Write the equation with correct formulas.
- Balance the equation with coefficients one element at a time.
- Check to ensure the smallest set of whole numbers is used.
Q: What are the six categories of chemical reactions?
A: Combination, decomposition, single replacement, double replacement, oxidation and reduction, and acid-base.
Q: Describe the difference between a combination reaction and a decomposition reaction.
A: A combination reaction joins two or more reactants to form a single product, while a decomposition reaction converts a single reactant into two or more products.
Q: What is a single replacement reaction? Provide an example.
A: A reaction where one element replaces another in a compound to form a different compound and element. Example: Zn + CuSO(_4) → ZnSO(_4) + Cu.
Q: What is a double replacement reaction? Provide an example.
A: A reaction where two compounds exchange parts to form two new compounds. Example: AgNO(_3) + NaCl → AgCl + NaNO(_3).
Q: What is oxidation and what is reduction in terms of electron transfer?
A: Oxidation is the loss of electrons, and reduction is the gain of electrons.
Q: Explain the concept of a redox reaction.
A: A redox reaction involves the transfer of electrons from one element to another, with one component being oxidized and the other reduced.
Q: What is the role of a reducing agent and an oxidizing agent in a redox reaction?
A: A reducing agent is oxidized and causes another compound to be reduced, while an oxidizing agent is reduced and causes another compound to be oxidized.
Q: What is a mole and how is it related to Avogadro’s number?
A: A mole is a quantity that contains 6.02 x 10(^23) items, known as Avogadro’s number.
Q: How can Avogadro’s number be used as a conversion factor?
A: It relates the number of moles of a substance to the number of atoms or molecules.
Q: How do you calculate the formula weight of a compound?
A: By summing the atomic weights of all the atoms in the compound.
Q: What is the molar mass and how is it used in conversions between grams and moles?
A: The molar mass is the mass of one mole of a substance in grams, used as a conversion factor between grams and moles.
Q: How do you calculate the number of molecules in a given number of moles of a substance?
A: Multiply the number of moles by Avogadro’s number (6.02 x 10(^23))
Q: How do you convert grams of a substance to moles using its molar mass?
A: Divide the mass of the substance by its molar mass.
Q: How do you convert milligrams of a substance to the number of molecules?
A: Convert milligrams to grams, then grams to moles, and finally moles to molecules using Avogadro’s number.
Q: How do coefficients in a balanced chemical equation relate to mole ratios?
A: They indicate the ratio of moles of each reactant and product in the reaction.
Q: How do you use mole ratios from a balanced chemical equation to convert between moles of different substances?
A: Use the coefficients from the balanced equation to set up conversion factors.
Q: How do you convert moles of reactant to grams of product using a balanced chemical equation?
A: Convert moles of reactant to moles of product using mole ratios, then convert moles of product to grams using molar mass.
Q: How do you convert grams of reactant to grams of product using a balanced chemical equation?
A: Convert grams of reactant to moles, use mole ratios to find moles of product, then convert moles of product to grams.
