Writing Formulae And Equations Flashcards
(11 cards)
What do scientists use to summarize the changes that occur in chemical reactions?
Formulae and equations
Formulae and equations help in communicating the details of chemical reactions clearly.
What charge do metals in groups 1, 2, and 3 typically form?
1+, 2+, and 3+ ions respectively
These charges correspond to the number of electrons metals lose to achieve stability.
What charge can non-metals in groups 5, 6, and 7 form?
3-, 2-, and 1- ions respectively
Non-metals gain electrons to achieve a full outer shell.
What must be true about the number of atoms on both sides of a balanced chemical equation?
They must balance
This is based on the law of conservation of mass, which states that mass cannot be created or destroyed.
What is the formula for calcium nitrate?
Ca(NO3)2
This formula indicates that one calcium ion combines with two nitrate ions.
How can you determine the number of bonds an atom will form in a covalent molecule?
8 minus its group number
This method helps predict bonding behavior based on the octet rule.
What is the formula for carbon dioxide?
CO2
This indicates that one carbon atom is double bonded to two oxygen atoms.
Fill in the blank: The equation for the combustion of methane is CH4 + _______ → CO2 + H2O.
O2
Oxygen is required for the combustion process to produce carbon dioxide and water.
What state symbol represents a solid in a chemical equation?
(s)
State symbols are used to indicate the physical state of the reactants and products.
What is the correct balanced equation for the reaction of sodium carbonate with hydrochloric acid?
Na2CO3 + 2HCl → 2NaCl + CO2 + H2O
This equation shows the conservation of mass with proper coefficients.
True or False: You can create or destroy atoms in a chemical reaction.
False
Atoms are conserved, and only rearranged during chemical processes.
