A mixture consisting of 12.4 g of calcium fluoride, CaF2, and 13.3 g of sulfuric acid, H2SO4, is heated to drive off hydrogen fluoride, HF.
CaF2(s) + H2SO4(l) ==> 2HF(g) + CaSO4(s)
What is the maximum number of grams of hydrogen fluoride that can be obtained?
I’m stuck on my science homework & need a little help. It says:
"The steps necessary to get pure salt from rock salt are listed below, but they are all mixed up.
Copy out the steps in the correct order:
Rock salt (a mixture of salt, sand and dirt) is crushed into small pieces.
The mixture is filtered
The solution is evaporated gently to leave dry salt.
Only the pure salt dissolves.
The mixture is warmed and stirred
The salt solution passes through the filter paper
Water is added to the mixture
The sand and dirt are trapped in the filter paper"
Can someone help me put them in the right order, cause I have no idea, lmao.
Is fluoride an element, a mixture of elements combined, what is it?
Why is it not in most of Europe’s drinking water when it is in America’s drinking water?
I really want to understand this stuff, so thanks for answering! Please answer appropriately as well!
I have some floating aquatic plants that may have snail eggs on them. Will unconditioned tap water kill them? Will it harm the plants? I could bleach the plants with a dilute mixture of bleach/water but if I can accomplish the same thing with a few days in a bucket of tap water, i would prefer that.
I have well water and would like to install my water softener in the basement. This being said a water softener that does not use salt would be perfect. I am also looking into a tankless water heater. Does anyone have any opinon on the matter? Should I use all propane in my new house or electric or a mixture?
1. A liquid is thought to be pure ethanoic acid. Which of the following is the best way to test its purity?
a. measure its boiling point b.react it with ethanol c. burn it completely d. dehydrate it with concentrated sulphuric acid
2. a bottle of copper(II) oxide, an insoluable salt in water has been contaminated with some solid sodium chloride. How can the sodium cloride be removed from the copper(II) oxide?
a. place the mixture in a separating funnel b.heat the mixture and allow it to cool c. add dilute acid to the mixture and filter d. add water to the mixture and filter
3. When candle wax is heated, it softens and then melts over a range of temperatures. Which statement explains this behaviour of them wax?
a. wax is a hydrocarbon b. wax is a lubricant c. wax is an insulator d.wax is a mixture
4. How would you adapt the distillation apparatus so that a flammable liquid could be purified?
5. Write a word to describe the change that takes place when you add salt to water and stir.
6. What is the advantage of using a locating agent in paper chromatography?
Ok, started off with a gallon of bourbon and added 8 pounds of pitted and skinned peaches. Sat that in a sealed carboy for 3 months and then mixed up a simple sugar compound of equal parts 2 cup honey & 2 cup water / 2 cup brown sugar 2 cup water then filtered and bottled the mixture in clean bottles. I had some of each left over and bottled then in separate containers. So I have 1 container of peach bourbon with honey, 1 of peach bourbon with honey and 1 of peach bourbon with a 50/50 mix of honey and brown sugar.
The pure honey bourbon is fine, the honey / brown sugar is somewhat thicker and the strickly brown sugar bourbon has developed a lava lamp like viscous transparent gel in the center of the bottle. When agitated or shaken it breaks up and has a consistency similar to the honey / brown sugar mix.
I have done the same process with cherries without similar effect so I assume it’s something about peaches and brown sugar?
Also, why does the water begin bubbling when dry ice is placed in the water. What is this mixture of water and carbon dioxide generally called?
1. A pure substance that decomposes gently when heated would be classes as:
a. an element
b. a metal
c. a non-metal
d. a compound
e. a mixture of elements
Which of the following processes could best be used to obtain pure water from a solution of sodium chloride and water?
a.Chromatography
b.Filtration
c.Decantation
d.Distillation
e.Evaporation
Which one of the following processes would be the most suitable for separating the different dyes from a sample of black ball point ink?
a. Chromatography
b.Distillation
c.Evaporation
d.Filtration
e.Decantation
A beaker of muddy water contains only dissolved salt and some suspended materials. Which one of the following procedures would be the best way to recover the pure salt?
a.filter first, then decant
b.decant first then filter
c.evaporate first, then filter
d.evaporate first, then decant
e.filter first, then evaporate
There’s a little pond with some dirty water, which is contaminated with soil, bacteria, mineral salts and rocks. You are allowed to use all basic lab equipment, like heat, magnet, filters, etc..
i need to find a way to separate the components of the mixture and obtain a pure sample of drinkable water, also, separate the salt for further use…
any ideas??
Well, the procedure follows:
-2 grams of PREVIOUSLY HEATED CuO and a corn-grain amount of sugar were grinded in a mortar.
-The mixture was transferred in a test tube and covered with a rubber stopper with bent glass tubing.
-The test tube was attached to an iron stand in an inclined position, and the other end of the glass tubing was immersed in 5ml Lime water.
-The test tube with the grinded mixture was heated with a bunsen burner.
A. copper. C. iron.
B. lead. D. aluminum.
2. When a concrete road is put down, black asphalt strips are
placed between sections of the concrete to
A. aid in night driving.
B. allow for the expansion and contraction of the concrete.
C. allow water to drain off the road.
D. prevent vehicles from skidding in icy weather.
3. Which of the following would not be classified as a fossil fuel?
A. Coal C. Oil
B. Sand D. Natural Gas
4. A mixture of all the colors of the spectrum would produce what color light?
A. Black C. Red
B. Blue D. White
5. An electric motor turns because the electricity passing through its coils produces
A. magnetism.
B. heat.
C. a chemical change in the coils.
D. sound.
6. Distillation produces water that’s
A. less pure than filtered water.
B. less pure than aerated water.
C. clear, but contains a high bacteria content.
D. chemically pure.
7. Water is an example of a/an
A. compound. C. element.
B. mixture. D. solution.
Thanks again for your help
