Burning 87.81 grams of hexane will release __ g of water.

__ c6h14 + __ o2 → __ co2 + __ h2o

= 128.772 g of water

2C6H14 + 13 O2 → 6CO2 + 14 H2O

1 mole of Hexane contains 86 g

Therefore;

87.91 grams of hexane will contain

= 87.91 g/86 g

= 1.022 moles

The balanced reaction for the combustion of Hexane is given by

2C6H14 + 13 O2 → 6CO2 + 14 H2O

Therefore; the mole ratio of C6H14 :H2O is

= 2 : 14

= 1: 7

therefore moles of water from 1.022 moles of Hexane will be;

= 1.022 ×7

= 7.154 moles

Mass of water will be;

= 7.154 moles× 18

= 128.772 g of water

The reaction will produce 128.772 g of water

The balanced chemical equation is written as

2C6H14 + 13 O2 → 6CO2 + 14 H2O

Finding the mole ratio of C6H14 :H2O we get

= 2 moles of C6H14 : 14 moles of water H2O

Simplifying it we get 1: 7

In this case moles of water from 1.022 moles of Hexane will be;

moles of water x moles of Hexane

= 1.022 ×7 = 7.154 moles

Now As we know

Moles = Mass / Molar Mass

Mass = Moles x Molar Mass

Mass = 7.154 moles× 18

= 128.772 g of water

there is none because earth is stationary and flat.

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.