Questions in Grade High-school

Questions in Grade High-school

[Done] A student investigated the rate of reaction between sodium thiosulphate and dilute hydrochloric acid. - The student placed a conical flask over a cross on a piece of paper. - The student mixed the solutions in the flask. - The solution went cloudy. - The student timed how long it took until the cross could not be seen. The equation for the reaction is: \[ \text{Na}_2\text{S}_2\text{O}_3(aq) + 2\text{HCl}(aq) \rightarrow 2\text{NaCl}(aq) + \text{H}_2\text{O}(l) + \text{SO}_2(g) + \text{S}(s) \] Explain why the solution goes cloudy.

[Done] Which is bigger, [tex]0.45[/tex] or [tex]\frac{2}{5}[/tex]?

[Done] Provide the steps to solve two-step equations.

[Done] How did Hongwu bring stability to China?

[Done] Thermosoftening polymers can be used to make plastic bottles and food packaging. 1) The reaction to produce polymers uses a catalyst. Why does the catalyst work for a long time before it needs replacing? 2) Thermosoftening polymers would not be suitable for packaging very hot food. Explain why in terms of their properties and structure.

[Done] The nerve pathway linking the heat receptor in the hand with the arm muscle is about 1.5 meters in length. It would take the nervous impulse 0.02 seconds to travel this distance along a neuron. However, it takes about 0.5 seconds for the arm to start moving during the reflex response to the heat stimulus.

[Done] One-fourth of the opposite of the difference between five and a number is less than 20.

[Done] Which group wanted Hayes to remove troops from the South?

[Done] What range of latitude does South America span?

[Done] Which trinomial is equivalent to \((3x-2)(x+4)\)?