All Questions

Filter by
Sorted by
Tagged with
0
votes
0answers
79 views

distillation of aqueous CAN solution for the purpose of a reversible and strong endothermic reaction in cool packs

I know calcium ammonium nitrate (CAN) is used for cold packs. By bending a small metal plate the salt gets dissolved in water (separated pack) and this process is endothermic. I would like to heat ...
2
votes
1answer
103 views

Designing a device to separate water from water-ethanol mixture using dry ice baths

I've been trying to design a device to increase the percentage of ethanol and water, or to at least concentrate the water-alcohol mixture without using distillation. The way I'm trying to do this is ...
3
votes
1answer
85 views

Function of water and the need of two barrels in a biogas Generator

For my chemistry assignment, I have to build a biogas generator. I found the following diagram, This is the website that the image is from: http://www.motherearthnews.com/renewable-energy/other-...
2
votes
2answers
1k views

Potassium Alum Crystals

This is a question regarding the crystallization of $\ce{KAl(SO4)2 . 12 H2O}$. I have an idea of what to do (I'll explain later in the explanation), but I would like to hear other suggestions encase ...
8
votes
2answers
956 views

What is the purpose of froth in washing clothes?

I stay at a rented place and there is no washing machine. I, now, wash clothes in a bucket. When I add detergent, sometimes there is froth, sometimes there is not. I wonder if this had any impact on ...
11
votes
9answers
1k views

How do I excel in Chemistry? [closed]

I wanted to ask an online group of experts/community about how I could improve in chemistry. I study in 10th grade currently and don't get very good grades. Most of the time its a B or C. I have to ...
0
votes
1answer
614 views

How to accurately calculate the electromotive force for various conditions in a salt water battery?

This question is on the same topic as this one but more complex. So, let's consider the cell with $\ce{Zn}$ and $\ce{Cu}$ electrodes inside the $\ce{NaCl}$ solution. On the $\ce{Zn}$ electrode we ...
1
vote
1answer
7k views

Why does steel wool catch fire when rubbed with a battery?

I was watching an episode of Man vs Wild where steel wool was rubbed with phone battery. To my surprise, the wool caught fire. What is the reason for this?
2
votes
0answers
395 views

How do I measure the density of a cellulose acetate membrane?

I've been playing around with filtration methods, and got my hands on a casting machine for this purpose. My first mission was to find out how porosity can affect filtration. To see this for myself, ...
2
votes
1answer
222 views

Solar still and how it works

I use a solar still that holds 182 cubic feet of water. Here is how it works: There is an insulator on both sides of the metal bowl. On the outside it covers the whole thing. on the inside it covers ...
7
votes
1answer
1k views

What is the reason a grain of salt alters the perceived bitterness of coffee by such a high degree?

Coffee served hot can be quite bitter (presumably high pH). Several people I have known will add a single grain of salt to the coffee - which reduces the perceived bitterness. My question is: What ...
5
votes
2answers
225 views

For a given teabag and dunking duration - will I get more caffeine in a bigger cup or the same amount?

When choosing a cup of tea, I can choose a big cup or a small cup. I'm wondering if I get more caffeine with the bigger cup or the same amount of caffeine. (in moles) My question is: For a given ...
3
votes
2answers
932 views

Why do hairs (rubbed with plastic comb) fallen on water seems to be sticking?

I was observing from many days, how hairs seems to be sticking to water, when made to fall on it. I made an attempt to know what really was going on. I kept a jug of stationary water under the light, ...
2
votes
2answers
360 views

Why do puffed rice stick to wet hands?

My mom gave puffed rice to eat, I had quite wet hands. I saw that, each puffed rice pieces started hanging to the hand, when I brought my hand in contact with them. I thought about electrostatics ...
2
votes
1answer
80 views

Reaction with carbon

Usually maximum time we see then after cooking by gas there is no black spot on the pot. But continually burning can affect the pot surface and makes black powder. My question is: What is the ...