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Obviously this student was in a bit of a hurry and missed the equivalence point by a substantial margin. :( If you add the last drops of NaOH slowly you should be able to achieve a precision of 0.1 mL in the aliquot. Look at the results at 20.0 mL and 24.0 mL. This is where the inflection...

Ahh, no. We call them liquids because that is their standard state at 25oC. If the ester coincidentally happens to be dissolved in a reaction mixture like an alcohol, then you still call it a liquid. The adjective "aqueous" (aq) should be reserved for substances that are dissolved in water, or...

Yes, it should be tan θ. I disagree with that equation given in the sample answer. The result is correct, but the equation is wrong. Here is the free body diagram of the car. The car is subjected to just two forces, they are W the force of gravity and FN the normal force from the road. The net...

Most esters are liquids at room temperature.

You state that gases are (g) and liquids are (l). Students are not required to memorise the physical states of organic compounds for the HSC Chemistry exam. You should be able to work these facts out from the context of the question. If a question requires you to write a chemical equation...

No you're not. You're doing just fine. Just make sure you read all parts of the question, and underline the important facts.

In the original post, it says Io is the intensity after leaving polarising filter #1. Therefore Malus' Law only applies to the interaction between polarizing filter #2 and filter #3. Therefore the intensity after leaving filter #3 varies from zero to 0.5 Io.

This is a common misconception, but the influence of the first polarizing filter over the third polarizing filter (or the second analyser if you want to refer to it that) is irrelevant once you introduce the middle polarising filter. I have done this experiment many times in class with three...

Yes, the intensity of the light will halve after passing through the first filter, but it will not halve after passing through the second filter. The law about halving the intensity only applies to unpolarised light that has passed through an ideal polarising filter. Once the light has become...

Regarding H, C and O. Look at those values for abundance. There is only one dominant isotope, the other isotope is totally insignificant for the mass spectrum, so no need to memorise those ones. Regarding those other elements, as part of your general knowledge in Chemistry, you should be aware...

First, we must assume that the wave fronts are drawn as if they are synchronous, that is they are generated at the same times. Next we look for places where the first wavefront from the left-hand source intersects with the third wavefront from the right-hand source, and draw a point. This is a...

H2O donates a proton to NH3. The Bronsted-Lowry model of a base is any substance that is a proton acceptor.

Obviously the wave fronts are separated the wavelength λ. Place numbers on the wave fronts radiating out from each source. Maximum constructive interference occurs where wave crests coincide. There are going to be multiple points where the wave fronts are out-of-phase by exactly 2λ. The points...

Yes, you nailed it. The only thing that we should add is the shape factor - the dispersion forces increase as the chain length increases, and they fall as the degree of branching increases hence the molecule tends to become more spherical in shape.

Yes, there is a lot of jargon around this topic. Complexation, as far as the HSC Chemistry course is concerned, refers to certain metallic cations that can become surrounded by a shell containing 4 or 6 negatively charged anions, or polar molecules with their delta-negative bits pointing towards...

Ahh yes, good point. therefore is impossible to transmit 60% of the original intensity.

Then we apply Malus' Law and make θ the subject of the equation. θ = cos-1( √0.6) which is about 39 degrees.

The question is supposed to be examining Malus' Law. If you just apply the equation I/Io=cos2θ = 0.5 However there is a trap buried inside this question that probably makes it invalid. Unpolarised light, presumably from the Sun, has reflected off the ocean and during this reflection it becomes...

There are many ways to perform this calculation; here is an alternative to @Luukas.2 Determine the mass factions of Cu and Cl in the compound CuCl2. This compound is 63.5 amu of Cu and 70.9 amu of Cl, so 47.2% Cu and 52.8% Cl by weight. Now let's look at Solution 2. Reading off the graph, and...

The other factor to consider is centripetal acceleration. The skateboarder is not just falling vertically under gravity, but executing a circular path. However, the velocity of the skateboarder is zero at point A and also diametrically opposite point A (maybe we should refer to as point C)...