Ms. crawford gave the following instructions to her science class: • place an empty water bottle on the table and remove the lid. carefully pour 10 ml of vinegar into the bottle. • open up the mouth of the balloon and have you lab partner spoon 1 teaspoon of baking soda into the balloon. • without spilling any of the baking soda, stretch the mouth of the balloon over the mouth of the bottle. • turn the balloon completely upright so that the baking soda inside the balloon pours into the bottle with the vinegar. watch! the baking soda looked like it dissolved in the vinegar. sarah and connor watched as the balloon expanded and filled with a gas. was this a physical or chemical reaction and why? a) chemical - gas produced b) physical - water bottle got hot c) physical - baking soda dissolved d) chemical - baking soda disappeared

Nconcentration refers to the molar concentration of an ion in solution. it may be identical to, or greater or less than, the molar concentration of the compound containing the ion that was used to make the solution. for soluble salts, the molarity of a particular ion is equal to the molarity of that compound times the subscript for that ion. for example, 1 m of alcl3 is 1 m in al3+ and 3 m in cl−. 1 m of (nh4)2so4 is 2 m in nh4+ and 1 m in so42−. part a what is the concentration of k+ in 0.15 m of k2s? view available hint(s) nothing m m part b if cacl2 is dissolved in water, what can be said about the concentration of the ca2+ ion? view available hint(s) if is dissolved in water, what can be said about the concentration of the ion? it has the same concentration as the cl− ion. its concentration is half that of the cl− ion. its concentration is twice that of the cl− ion. its concentration is one-third that of the cl− ion. part c a scientist wants to make a solution of tribasic sodium phosphate, na3po4, for a laboratory experiment. how many grams of na3po4 will be needed to produce 550 ml of a solution that has a concentration of na+ ions of 0.700 m ? express your answer numerically in grams. view available hint(s) mass of na3po4 n a 3 p o 4 = nothing g provide feedback