Chapter 7 - Chapter 7: Chemical Reactions 7.1 o...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 7: Chemical Reactions 7.1 o Kindergarten volcanoes, automobiles, and laundry detergents Chemical reaction: the change of one or more substances into different substances Chemical reactions can be relatively simple, like the combination of hydrogen and oxygen to form water, or they can be complex, like the synthesis of a protein molecule from thousands of simpler molecules Chemical reactions produce changes in the arrangements of the molecules and atoms that compose matter. 7.2 o Evidence of a chemical reaction Color changes Formation of a solid Formation of a gas Heat absorption or emission Light emission 7.3 o The chemical equation Chemical equation: a way of representing a chemical reaction + + CH4 O2 CO2 H20 reactants Products Reactants: the left side of a chemical equation (pre reaction) Products: the right side of the chemical (post reaction Balanced equation: add coefficients rather than subscripts to ensure that the number of each type of atom on both sides of the equation is equal.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
the number of a particular type of atom within a chemical formula embedded in an equation is obtained by multiplying the subscript for the atom by the coefficient for the chemical formula 7.4 o How to write a balanced chemical equation Remember: change only the coefficients to balance a chemical equation, never the subscripts. 1. Write the skeletal equation by writing chemical formulas for each of the reactants and products. 2. If an element occurs in only one compound on both sides of the equation, balance it first. If there are more than one such element, balance metals before nonmetals 3. If an element occurs as a free element on either side of the chemical equation, balance it last. Always balance free elements by adjusting the coefficient on the free element. 4. If the balanced equation contains coefficient fractions, clear these by multiplying the entire equation by the appropriate factor. 5. Check to make certain the equation is balanced by summing the total number of each type of atom on both sides of the equation 7.5 o Aqueous solutions and solubility: compounds dissolved in water Aqueous solution: a homogeneous mixture of a substance with water. When ionic compounds such as NaCl dissolve in water they usually dissociate into their component ions. A NaCl solution, represent as NaCl(aq), does not contain any NaCl units, but rather dissolved Na + ions and Cl - ions.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

Chapter 7 - Chapter 7: Chemical Reactions 7.1 o...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online