# All Questions

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11 views

### How do you use MacConkey's agar to test yogurt? [closed]

I am in Secondary school and we are testing radiation effects on yoghurt and one thing my teacher reccomended was testing through MacConkey's agar to see what happens. 1) Can someone explain in lay ...
36 views

### Method for making graphene by reducing carbon dioxide on gallium surface [closed]

I had an idea where you take gallium in a vacuum and while it’s under a vacuum you spread it out across a flat surface such as a glass slide. You would want to spread it while under a vacuum to ...
22 views

### Differences Between RainX and RainX Anti-Fog? [closed]

I have a question pertaining to chemistry in a practical way. As I was unable to find a more suitable community to ask, I shall ask it here. RainX, as you may already know, is a compound applied to ...
29 views

### Obtaining conformational energy from Newman projections in first place

In this source, the conformational energy from Newman projections is obtained. Is there a formula or quantum chemistry approach to obtain the values in first place (pretend that I don't know the ...
28 views

### Surface modelization of an electrode

I am trying to model the interaction between an electrode and a saline solution through an RC circuit. A reference electrode is placed in the saline solution to measure the voltage between the ...
45 views

### Reaction between CuSO4.5H2O and NH3 [on hold]

Today in the laboratory we did a confirmatory reaction for Copper (II) in CuSO4. The reaction we carried out was adding NH4OH to a little of original salt solution. So the reaction that took place is ...
71 views

### What happens when a super-critical fluid is compressed?

Suppose that I have some substance with a critical temperature of 20°C. That means above that temperature, the substance exists neither as a gas nor a liquid, but instead as a super-critical fluid. ...
32 views

### CNDO/2 clarification

I wrote a piece of code on RHF using Python a while back, and figured I'd extend it to also implement CNDO/2 (yes, I know it's old but I figured it'd be easier for me.) The approximated Fock matrix ...
21 views

### Why is BF3 hard while BBr3 is borderline(HSAB concept)?

This is a table given in a text book regarding hard acids How come BF3 is a harder acid than BBr3? My reasoning: To check which is harder: 1.Both difficult to polarize 2.Both similar in size It ...
12 views

### C-C bond lengths in hydrocarbons

We had a question in a rest comparing the bond lengths of hydrocarbons fluorides, and the answer key says CF3- CF3's supposed to have a longer C-C bond than H3C- CH2--F. Why is this so? Wouldn't the ...
23 views

### Is the nature of both the ligands, PH3 and PF3, non-classical?

A non-classical ligand is defined as: ligand which forms complexes with transition metals only but not with other metals. $\ce{PH3}$ and $\ce{PF3}$ both are $\pi$ donor (due to lone pair with $P$ ...
30 views

### How do elemental halogens get their colour?

I learnt that in halogens the colour is due to transfer of electrons from HOMO to LUMO during excitation but I have trouble understanding what that means. Also I don't understand how iodine is ...
21 views

### Name of Nonmetal Polyatomic Ions [duplicate]

I'm studying for a high school chemistry test and I wanted to put a name to polyatomic ions which contain a nonmetal and oxygen. Examples include phosphate, sulfate, nitrate, ... etc. I have ...
39 views

### Chirality as atom feature

I have been reading some literature on molecular energy prediction using machine learning techniques and I have noticed that one of the input parameters in many of the available models is "chirality". ...
58 views

### Safe, low maintenance, versatile methods for electro-etching steel?

I'm experimenting with electro-etching steel. I'd like to mask off a small area (e.g. text or logo with exposed area of about 2cm x 2cm) on a steel sheet, and etch about 1mm deep. I'm trying to find a ...