Lab Report: Predicting Precipitation

Finally ensure that your results are accurate. You should have a light blue precipitate remaining when the sodium carbonate reacts with the copper chloride and when sodium sulphate ionises with copper chloride no precipitate should have formed.

These were most likely impurities, in which case I added a bit more water than was necessary. Also, the lab manual says to take two samples of each mixture (unknown; ½ phenacetin; ½ acetanilide) for the melting point, but we only conducted one.

In part 1, the precipitate that forms is a aluminum hydroxide and in part 2 it is magnesium hydroxide. A precipitate is an insoluble solid that emerges from a liquid solution. When the emergence of the insoluble solid from solution happens, it is called precipitation. The property change in the reactants of the lab are when the water, alum, ammonia, react and create the aluminum hydroxide. When the precipitate is formed, it is an endothermic reaction because the change in the product, aluminum hydroxide, decreases in temperature. This is a chemical reaction because different elements rearrange themselves to form a new substance and while they do so, they either absorb heat or give it

Many signs show that a chemical reaction has occurred. Some ways we know there is a chemical reaction are the formation of gas, formation of precipitate, change in temperature, and,or change in color. In part one of the experiment, we know there was a chemical change because of the formation of the white precipitate. We poured the ammonia and water in the flask with alum and water, forming a white, cloudy substance in between the two liquids. The white, cloudy substance between the two is liquids is also known as aluminum hydroxide. The second part of the experiment was very similar to the first, but in the second part we mixed epon salt, water, and ammonia. The precipitate formed from mixing the epson salt, water, and ammonia was called magnesium hydroxide.

The objective of the experiment was to observe different reactions with different chemicals. The experiments emphasized on the chemical changes occurring in acids and bases as well as color changes and bubble formations. The experiments allowed for a better understanding of the undergoing chemical changes in mixtures. Some mixtures instantly changed colors while others were transparent or foggy. Some mixtures produced thick color that created solids called precipitates. Mixtures KI + Pb(NO3)2 and NaOH + AgNO3 both produce noticeable precipitates after a while. It was interesting to see the different acidic and base reactions like the fuchsia color formation in NaOH + phenolphthalein.

to the unknown solution in order to completely precipitate the cations in part A. 2 A compound

The Vitamin C turned to a red/orange color with no physical/chemical reaction. For the salt the solution turned to an orange color with no physical/chemical reaction. With the Alka-Seltzer, the solution turned to a brown color with no reaction as well. Last but not least, the Baking soda turned to an orange/brown color with no reaction.

The precipitate was AgCl (Silver Chloride). The color of the precipitate was white. Copper Dichloride + Lead Dinitrate formed a precipitate. The precipitate was PbCl2 (Lead Dichloride) and the color of this was blue. Ammonium Sulfate + Lead Dinitrate also formed a precipitate.

Precipitate can emerge in the form of a

Try to use exact amounts of the starting reagents to ensure that the reaction is carried to completion. Also, make sure the solid fully dissolves so that no impurities are present in your solution. A water condenser is used to remove excess water from the reaction since it is a by-product and heat from the reaction. Be sure to note any color changes or other physical properties that occur throughout the experiment. Overall, this is an example of a green experiment because only two reactants were used without the addition of any waste products to form the expected

When two solutions combine and a solid substance is formed, this solid is called a precipitate. In your experiments, if the clear reactant solutions you combined together formed a cloudy product, then a precipitate (solid substance) was formed. Describe the precipitates (according to color and clarity) and the substances that formed them. (18 points) The combinations that formed precipitates in my experiment were MgSO4 and NH3, MgSO4 and Na2CO3, Na2CO3 and CH3COOH.

Capricorn Anderson lived on Garland Farm outside of San Francisco, California with his hippie grandmother, Rain. One day Rain falls out of a tree while picking plums and has to go to the hospital. Cap has to move in with a guidance counselor and her daughter which he thinks is very beautiful. Cap is put in Claverage Middle School or C Average as the student call it. Cap has a hard time fitting in with the other students. One the first day Cap meets one friend Hugh Winkleman, a nerd. In eighth grade the student all pick the biggest nerd to be the eighth grade president. Cap is very confused when he is elected. Zach Powers, the most popular guy in school, takes him to a fake student council meeting in a classroom that was not real. Cap starts

Each one of them has a precipitating agent. For example, ferric chloride has a precipitating agent in the form as hydroxide Fe (OH)3 which has a reddish brown color. Fe3+ + 3OH- → Fe(OH)3 ↓ Chromium chloride has a precipitating agent as Cr(OH)3 which has a dirty green color. Cr3+ + 3OH- → Cr(OH)3 ↓ Aluminum chloride has a periciptating agent as Al(OH)3 which has a white gel color. Al3+ + 3OH- → Al(OH)3 ↓

Heavy precipitate emerged immediately and solution turned white in color; solution then became opaque and turned light, bright blue in color.

Soil moisture also affects the yield and competitiveness of the introduced strain. Cowie et al. (1996a, b) reported that waterlogging at any time have an adverse effect on the seed yield. Drought conditions severely affect the viability of different species and strains of rhizobia (Joshi et al., 1981; Osa-Afiana and Alexander, 1982). Singh et al. (1992) reported that at a available soil moisture of 45 per cent nodule number and dry weight of nodules increased while at 30 per cent available soil moisture, seed yield increased. Strains isolated from arid areas are more tolerant to dessication and high temperature than strains isolated from cooler and wet region. Bitorrini and Beringer (unpublished, cited by Dowling and Broughton, 1986)