Acids and Bases

Cation

positively charged

base

- a chemical compound that dissociates into hydroxide ions - produces hydroxide ion (OH-) - positively charged ion when mixed with water - water can be both an acid and a base - has at least 1 oxygen and 1 hydrogen atom in their chemical formula

ph

- a chemical property of matter - involves both acids and bases containing an excess of either H+ or OH- ions

Hydrogen ion

- a hydrogen atom that has lost 1 electron, so only the nucleus and its single proton remain. -When an acid is mixed with water, it dissociates into a negatively charged ion and a hydrogen ion, H+.

ph scale

- a linear scale that allows a scientist to measure the concentration of hydrogen ions. - starts at 0 represents a high concentration of hydrogen ions - goes to 14, represents a low concentration of hydrogen ions

muscle layer

- aids in the mechanical mashing and compaction of food materials

how is food broken down?

- by a combination of mechanical digestion (caused by muscular movements) and chemical digestion (caused by gastric acid or HCl) that breaks down foodstuff before it moves on to the small intestin

how do you decrease the concentration of hydrogen ions in acidic solution

- by diluting the solution - to perform a chemical reaction by dissolving both an acid and a base in water

how do ulcers form in the stomach or acid reflux?

- by excessive stomach acid

Characteristics of Acids

- has at least 1 Hydrogen(H) atom that produces hydrogen ions (H+) when mixed with water - produce hydronium ion (H+) -chemical properties of acids results from the production of hydrogen ions which are very reactive - react with metals - creates hydronium ion - has a strong smell - has a sour taste - can burn or sting skin

what increases solubility?

- increasing solvent amount - Shaking/stirring, increasing temperature and pressure, decreasing particle size (increasing surface area),

the lumen

- inside compartment of the stomach is lined with cells that secrete gastric acid (HCl) but also cells that secrete mucus that acts to protect the stomach lining itself from HCl.

3 ranges of the pH scale

- neutral = centered at a pH 0f 7 - acidic range = lower than 7 -basic range = above 7

characteristics of bases

- tastes bitter - feels slippery - can burn skin - can dissolve things - can be poisonous

how do you decrease the concentration of HCl in the stomach?

- to use an antacid medication that neutralizes the acid - the medication contains bases that produce hydroxide ions which react with excess hydrogen ions to produce water resulting in a more neutral pH in the stomach

how is acid rain produced?

- when coal is burned in power stations to produce electricity. the power stations release fumes into the air which contain gas sulfur trioxide. then the sulfur trioxide combines with water in the atmosphere to form sulfuric acid which dissolves in rain as it falls to the ground

hydrochloric acid (HCl)

- will dissolve in water and produce hydrogen ions - a hydrogen ion and a negatively charged chloride ion are produced

Concentration

-the amount of anything dissolved in a solution -the ratio of the amount of solute to the volume of solvent - usually expressed as a certain mass or volume of solute dissolved in 1 millilter

What properties make acids and bases chemically reactive?

Acids release H+ions when they are mixed with water and bases remove H+ ions when they are mixed with water.

What is the relationship between the pH of a solution and the concentration of hydrogen ions (H+)?

As the pH of a solution increases, the concentration of H+ions decreases. An increase of 1 pH unit decreases the concentration 10 times. As the pH of a solution decreases, the concentration of H+ ions increases. A decrease of 1 pH unit increases the concentration 10 times.

what does neutralization produce?

Produces a salt and water. HCl + NaOH = H2O + NaCl

What increases solubility?

Shaking/stirring, increasing temperature and pressure, decreasing particle size (increasing surface area), increasing solvent amount

What is the relationship between the concentration of H+ ions in a solution and the chemical reactivity of strong and weak acids?

Stronger acids are able to release more H+ ions when mixed with water resulting in a higher concentration of H+ ions. Weaker acids release fewer H+ ions resulting in a lower concentration of H+ions.

What is the relationship between the concentration of H+ions in a solution and the chemical reactivity of strong and weak bases?

Stronger bases are able to remove more H+ ions when mixed with water resulting in a lower concentration of H+ions. Weaker bases remove fewer H+ ions resulting in a higher concentration of H+ions.

What happens to the concentration of hydrogen ions (H+) when an acid and a base are reacted?

When an acid and a base react, H+ ions and OH- ions react to produce water and decrease the concentration of H+ ions.

Acids

a group of chemical compounds that produce hydrogen ions (H+) when mixed with water.

solution

a mixture of two or more substances that is homogeneous or the same throughout

serial dilution

a stepwise dilution of a substance in solution and allows for the accurate preparation of extremely dilute solutions

soluble

able to be dissolved by a particular solvent

examples of acids

any citrus juice, vinegar, hydrochloric acid, milk

examples of bases

any soaps or cleaners, baking soda, blood, antacids

Compare acids and bases

both conduct electricity, both can burn at high concentrations

parietal cells

cells that actually produce and secrete HCl

Ions

chemical compounds that have either a positive or a negative charge

high concentration

dissolving a large amount of solute in a certain volume

low concentration

dissolving a small amount of solute in the same volume

precipitate

forms when a solvent is saturated and more solute is added. The extra solute 'precipitates' to the bottom

anion

negatively charged

insoluble

not able to be dissolved by a particular solvent. Some things can be dissolved by water and some cannot (insoluble)

heterogeneous mixture

not the same throughout (each scoop has different amounts of each solute compared to each other and to the solvent). Trail mix, chocolate chip cookies, salad...

what is the pH of the stomach?

pH between 1 and 2

concentration of a solute

the amount of solute that is dissolved in a certain volume of solvent to make a solution

relationship between concentration of hydrogen ions and pH

the greater the concentration of hydrogen ions, the lower the pH and the more acidic (less basic)

homogeneous mixture

the same throughout (each scoop has the same amount of each solute and solvent). Salt water, koolade, cake mix without swirls and such...

solute

the substance that changes state when a solution is prepared or is present in the smallest amount

solvent

the substance that does not change state when a solution is prepared or is present in the largest amount

function of the stomach

to promote digestion of ingested food material in and acidic environment - stomach acid (HCl) is secreted into the stomach

neutralization reaction

when a base and an acid are both dissolved in water - reaction forms a water molecule and a salt and reduce the hydrogen ion concentration and the pH increases to a more neutral pH - a greater concentration of base dissolved in water results in a lower concentration -

hydroxide ion

when a base is mixed with water, it dissociates into a positively charged ion and a hydroxide ion

dissociate

when a chemical compound is dissolved in a solvent, usually water, and separates into two or more ions

dilution

when a less concentrated solution is prepared by adding additional solvent

saturated

when a solvent is 'full' of solute and cannot dissolve any more

sodium hydroxide

will dissolve in water and produce hydroxide ions and a positively charged sodium ion