Calcium Definition and 80 Threads

Hey Guys, Just curiosity, but if a metal surface has a build up of calcium does this mean there is a higher chance of corrosion occurring? Or can it accelerate corrosion? Or is the build up on the surface of metal generally harmless?

How do u derive a general formula (without undue approximations) to calculate the solubility of CaCO3(s) in a aqueous solution at any pH? Thanks

Can anyone give me some insight into any materials/substances that might bond to calcium fluoride (CaF2)? Any help is appreciated, thanks.

Hi! I have heard this many times, even from quit educated people, that lack of calcium causes brittle nails. I know that nails contain protein - keratin, not calcium. And even if the body lacked calcium resorption from bones would first happen? So I don't see how it can cause brittle nails, but...

I was told to design an experiment and run it during my chemistry lab period, and I came up with the following idea: Soil usually is limed with calcium carbonate containing products (agricultural lime) in order to raise the pH of the solution. Thus, I first isolated the amount of calcium from...

Homework Statement Large electric fields in cell membranes cause ions to move through the cell wall. The field strength in a typical membrane is 1.0x10^7 N/C. What is the magnitude of the force on a calcium ion with charge +e? Homework Equations E = F/q > F = Eq The Attempt at a...

Hi, I am trying to write a model that simulates calcium input and output based on the induced strain, strain rate, and frequency of the applied strain. But before I can do that, I am trying to know more about the biophysics of the cell. How does the calcium pump/channel physically react...

Ksp of Calcium Hydroxide - A Percentage Error of 480%?? Homework Statement I did a titration between HCl and Ca(OH)2. I use the indicator Phenopthalein I did most of my calculations and thru repeated checking cannot find any significant error in my calculations. However, upon...

Thank you in advance for the correction of the resolution. Homework Statement By reacting 225 g of hydrochloric acid with 300 g of calcium carbonate with 80% of purity, 34 L (litres) of gas were obtained, measured at 37oC and a pression of 0.82 atm. What is the yield of this reaction and what...

Just a quick question about error analysis. Moles of Calcium ions in 10 mL = 6.0 x 10-4 ± 0.5 x 10^-5 mols I'm suppose to scale this number to Moles of Calcium ions in 250mL. So when I multiply by 25, do I multiply the error value as well? Or does it remain the same?

When glycerinated rabbit muscle fiber was placed in 10^-4 M of CaCl2 solution, the percent change in length of the muscle fiber was around 93%. When glycerinated rabbit muscle fiber was placed in 30 mM ATP in 10^-2 M CaCl2 + 0.05 M KCl + 0.001 M MgCl2 solution, the percent change in length of...

To whom it may concern, I have been unable to find data on the dissolution rate of calcium aluminate in a melt of calcium chloride at 700 degrees Celsius. The problem has been that I am aiming towards constructing a electrical furnace to melt calcium chloride with calcium metal and run...

Is it true that chocolate makes it harder for the body to absorb calcium? Someone told me that by drinking chocolate milk you hurt your bones more than you help them.

any ideas of which experiments best illustrate this Homework Statement Homework Equations

I just finished a lab and I was wondering if anyone could point out where I'm going wrong. Here are my findings for CaSO4: After First Heating After Second heating Wt. of crucible, lid, and hydrate 35.0537g...

What physically happens to the water when you heat CaCl2*2H2O above it's decomposition temperature 175 deg C? Does the water just vaporize? Or does it partially dissolve some of the calcium chloride in an aqueous solution and then boil away?

was asked to consider the solubility for hydrated calcium sulfate in HCl. The principal acid my proffesor had posted for the solution was [ CaSO4(hyrdrated) + HCl <--> H30^+ + Ca^2+ + SO4^2- ]. I guess what I'm asking is what happened to the Cl^- and why isn't it reacting with Ca^2+ to produce...

During qualitative analysis of Barium, Strontium, Calcium, why do we use NH4CO3, NH4OH, NH4Cl. Even if we were to apply common ion effect, two NH4+ ions are enough right? What is the need for third one?

Homework Statement This is a pretty simple problem... Yet I got the wrong answer.. Hmm... "Find the threshold frequency for a calcium surface whose work function is 3.33eV" W=3.33eV = 3.33eV * 1.6x10^-19 J = 5.33x10^19 J f = ? h=6.63x10^-34 J*S Homework Equations f=W/h The Attempt at a...

Caffeine & Dichloromethane What are the products of caffeine & dichloromethane? I think caffeine is acting as the acid, and dichloromethane as the base. So, the caffeine is releasing H+ into the solution. So would the equation be: C8H10O2N4 + CH2Cl2 --> C8H9O2N4+ + (I have no...

Calcium is essential in the prevention of bone loss. This is particularly important for women who are approaching menopause as they're susceptible to osteoporosis. I'm not sure what age women should begin incorporating more calcium into their diet but I do know that they need more after...

Do vitamins, calcium and vitamin c suppliments really work?

Calcium Carbonate is heated in a closed vessel, and an equilibrium is reached. CaCO3 (s) <=> CaO(s) + CO2 (g) At 500 C the equilibrium pressure of carbon dioxide is 1.2*10^-3 atm and at 1000 C it is 3.87 atm. what is the equilibrium constant for this reaction at 500 C? :confused:

hey, I've got a question. How do I write out the word equation Calcium + Calcium Nitate → ?. I haven't done one like this with the same metal before. Since they are on the equal level of the activity series, what happens? When I did the lab, there was a reaction so...I'm confused o-O

I know this isn't a physics problem, but it's due tomorrow and I'm really stuck :( Calculate the mass, in grams, of calcium ion dissolved in the water of a 40.0 gallon hot-water tank saturated with calcium phosphate. (Ksp calcium phosphate = 2.0e-29, 1.00gal=3.80L). >> I'm really lost...

Hey guys I've a quick question. As an action potential propogates down an axon, as it reaches the end of an axon it causes calcium influx into the terminal end of the axon. This calcium helps the vesicles move towards the pre-synaptic membrane so that they can release neurotransmitters. My...

Calcium chloride exists as dihydrate (CaCl2x2h20). it has 2 valence. according to the definition of valence: "valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a...

Could someone help with a way (or method) of how to determine the content of calcium in milk at a high school level.

Why would someone have extremely sweaty hands all the time.. ? Second Question... does calcium really provide anything for teeth... does it help to drink milk or anything..?

what experiment should i conduct to compare the amounts of calcium carbonate in 2 different shells... i believe this might be of use: acid + carbonate = salt + water + carbon dioxide my email is janice_ling88@yahoo.com.sg