Which procedure would best allow a scientist to observe a chemical property of hydrochloric acid (hcl) solution? cooling the hcl solution until it becomes solid, and measuring this temperature adding zinc to the hcl solution and observing whether or not bubbles are produced placing a conductivity probe into a beaker of hcl solution to determine if it conducts electricity measuring the mass of and volume of a sample of hcl solution to find its density

Adding zinc to the HCl solution and observing whether or not bubbles are produced.

A change in property that can be observed or can be measured without changing the substance's composition chemically is known as physical property. For example, change in temperature, change in state, change in mass, volume etc.

A change in property due to change in the chemical composition of the substance is known as chemical change. for example, when two substances react with each other and a chemically different product of formed.

→cooling the HCl solution until it becomes solid, and measuring this temperature- Physical change

→placing a conductivity probe into a beaker of HCl solution to determine if it conducts electricity-Physical change

→measuring the mass of and volume of a sample of HCl solution to find its density-Physical change

→adding zinc to the HCl solution and observing whether or not bubbles are produced-Chemical change:This would allow scientists to observe chemical property of HCl solution.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s