Check my answer? students observed that their teacher's desk plant looked wilted on monday morning compared to how it looked at the end of the day on friday. some students hypothesized that a warmer room temperature over the weekend caused the plant to wilt. other students hypothesized that the lack of light caused the plant to wilt. both hypotheses are valuable because they a.) are reasonable and testable (my answer) b.) compare independent variables c.) compare light and temperature d.) are the only possible explanations.

A.) are reasonable and testable

A hypothesis can be defined as the supposition or assumption of scientific process that is based on limited scientific evidences and used as a starting point for further investigation. The hypothesis needs to be proved by following relevant scientific methodology.

In the given situation, both the hypothesis are correct because both warm temperature and sunlight are genuinely responsible for wilting of plant in nature. The effect of both sunlight and warm temperature can be tested separately on plant. This proves that the hypothesis are reasonable and testable.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol