Category: chemistry

Chemistry: hygroscopic

Tutoring chemistry, definitions are important. The tutor mentions the term hygroscopic. hygroscopic (adj):readily collecting water, including water vapor. A sample of hygroscopic material can draw in water from the air, thereby gaining mass invisibly as it sits, uncovered, on the

Chemistry: anhydrous

Tutoring chemistry, definitions are always of interest. The tutor brings up the term anhydrous anhydrous (adj): containing no water. As I understand, the particles of an anhydrous substance are not associated with water, but likely would be if not for

Chemistry: what is a zeroth-order reaction?

Tutoring chemistry, reaction order is a topic. The tutor mentions the idea of zeroth-order reaction, with an example. A zeroth-order reaction is one that proceeds at the same rate even if the concentration of reactant is increased. Of course, there

Warming ice, melting ice, and cooling water

Tutoring chemistry, heat flow between hot and cold substances might be studied. The tutor mentions a reflection about water and ice. Today, while thawing chicken breasts in water, I wondered how much water would be needed to supply the necessary

Natural gas vs propane: part 0

Self-tutoring about common fuels: the tutor makes an initial comparison of natural gas to propane. Natural gas is chiefly methane, CH4; propane is C3H8. The combustion equation for methane: CH4 + 2O2 → CO2 + 2H2O Propane’s combustion equation, on

Flash point vs fire point: what is the difference?

Self-tutoring about safe temperature to heat cooking oil led the tutor to seek the difference between flash point and fire point. At the flash point, the vapor is ignitable but will only burn with a continuous source of ignition. At

Chemistry: acid nomenclature: hypo acids

Tutoring chemistry, naming acids might arise. The tutor brings up a time to use hypo in naming an acid. From a simple point of view, the hypo acid has one less oxygen than the -ous acid. For example: chlorous acid:

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Biology: what mineral form of calcium is found in bones?

Tutoring biology, the question about calcium in bone – specifically, which mineral form it takes – might arise. The tutor discusses it. The hardness of bone comes from the presence of hydroxyapatite: hydroxyapatite: Ca5(PO4)3OH found in bones and giving them

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Chemistry: what are degenerate orbitals?

Tutoring chemistry, you sometimes cover bonding. The tutor defines degenerate orbitals. Degenerate: being two separate objects with a single, identical value. The 1s orbitals of two separate hydrogen atoms are degenerate because, isolated from each other, they share a single,

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Chemistry: disproportionation

Tutoring chemistry, you likely touch on redox. The tutor shows a disproportionation. disproportionation: a reaction in which the same species both oxidizes and reduces. Example: Cu+ → Cu2+ + e– E=-0.153 Cu+ + e– → Cu(s) E=0.521 The above disproportionation,

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