1. what would you expect the pH value for grapefruit juice to be? (>7, 7, <7)
2. A.) Which two ions are present in very small amounts in any sample of pure water?
b.) what is a good alternative chemical formula for water rather than H2O? Why?
c.) with respect to ion count, why is water considered to be neutral?
3. How do the number of H+ and OH- ions compare after
a.) HI is added to water?
b.)KBr is added to water?
c.)KOH is added to water?
4. Give the Arrhenius definitions for acids, bases, and salts.
1. sour, acid <7
2. H+ and O-2 sort of H3O+ and O-2 is another way to look at it
2 b H O H because that is shape of molecule
2 c same number of 2 H+1 as O-2
3 a H+ up
3 b beats me, why should it change?
3 c OH- up, what else is new?
4 http://facultyfp.salisbury.edu/dfrieck/htdocs/212/rev/acidbase/arrhenius.htm
Thank u so much :)
You are welcome :)
1. To determine the expected pH value of grapefruit juice, you can consider its taste. Citrus fruits like grapefruit are usually acidic, which means they have a pH value less than 7. Therefore, you would expect the pH value for grapefruit juice to be less than 7.
2. a.) The two ions present in very small amounts in any sample of pure water are H+ (hydrogen ions) and OH- (hydroxide ions).
b.) The chemical formula H2O is the standard representation for water because it accurately reflects its molecular structure. Each water molecule consists of two hydrogen atoms bonded to one oxygen atom, hence H2O. Although there could be alternative chemical representations, they would not correctly represent the molecular composition and structure of water.
c.) Water is considered to be neutral with respect to ion count because it contains an equal number of H+ and OH- ions. In pure water at room temperature, the concentration of H+ ions and OH- ions is approximately 10^-7 moles per liter each. Since the concentration of both ions is equal, water has a neutral pH value of 7.
3. a.) When HI (hydroiodic acid) is added to water, HI dissociates into H+ and I- ions. This increases the number of H+ ions and decreases the number of OH- ions in the solution. Therefore, the concentration of H+ ions will be higher than OH- ions.
b.) When KBr (potassium bromide) is added to water, it dissociates into K+ and Br- ions. Neither K+ nor Br- ions contribute to the concentration of H+ or OH- ions. Therefore, the number of H+ and OH- ions remains unchanged.
c.) When KOH (potassium hydroxide) is added to water, it dissociates into K+ and OH- ions. This increases the number of OH- ions and decreases the number of H+ ions in the solution. Therefore, the concentration of OH- ions will be higher than H+ ions.
4. The Arrhenius definitions for acids, bases, and salts are as follows:
- Acids: According to Arrhenius, acids are substances that release H+ (hydrogen) ions when dissolved in water. They increase the concentration of H+ ions in an aqueous solution.
- Bases: Bases are substances that release OH- (hydroxide) ions when dissolved in water. They increase the concentration of OH- ions in an aqueous solution, either by reacting with water molecules to produce OH- ions or by releasing directly.
- Salts: In Arrhenius' definition, salts are compounds formed by the reaction between an acid and a base. They consist of a positive ion from a base and a negative ion from an acid. Salts do not directly contribute to the concentration of H+ or OH- ions in solution.