15. Use the information below to answer the following question(s). Four groups of students were each given a piece of aluminum foil (20 cm 20 cm), a container holding one liter of water, and some pennies. Each group was instructed to use the aluminum foil to make a boat that would hold the greatest number of pennies while floating on the water. The dependent variable in this investigation is the: A. amount of water.
B. number of pennies.
C. size of the aluminum foil.
D. length of the boat.

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

What volume would 2.25 moles of ne has occupy at stp?

For a family dinner, jose’s mom baked a loaf of bread. during the meal, his grandmother commented, “this bread is so dense! ” what do you think his grandmother meant by the word dense? you have some ideas regarding density already, but this experiment will enrich your understanding of the relationship between mass, volume and the density of objects. when making measurements in this experiment we will be using si units, the international system of units. the purpose of using si units is to have the ability to communicate and compare data results with other experiments without having to make conversions. measurement symbol si unit length m meter mass kg kilogram volume l liters density kg/l kilograms per liter any calculations that are performed during this experiment will ultimately be reported in scientific notation. recall that scientific notation is extremely important when we have data that is extremely small or large. scientists rely on a standard form of communication to quickly make hypotheses and judgements based on data. what is the density of block a? a0kg/l what is the density of block b? a1kg/l what is the density of block c? a2kg/l what is the density of block d? a3kg/l what is the density of block e? a4kg/l which block is the densest? a5