How can I convert a concentration in "mg/ml" to mM?
YOu will have to know the molar mass of the compound.For example, the normal value of blood glucose is 90 mg/100ml or 0.9 mg/ml. The molar mass of glucose is 180 g/mol. The molar concentration is then:(0.9 mg/ml)/(180 g/mol) = (900 mg/l)/(180 g/mol) = 5 mmol/l = 5 mMNote that 1 M = 1 mol/l and 1 mM = 1 mmol/l, where 1 mol = 1000 mmol.
How to find the unknown weight of any object using density factor?
im a rigger (work with crains) i know it starts lenth by width by hight miltiplied by 500 then the density factor of .02,.03 ect. or something close to this equation
Which equation can be used to determine c, the unknown concentration?
Two solutions of different concentrations of acid are mixed creating 40 mL of a solution that is 32% acid. One-quarter of the solution is made up of a 20% acid solution. The remaining three-quarters is made up of a solution of unknown concentration, c. Which equation can be used to determine c, the unknown concentration? 30c + 10(0.2) = 40(0.32) 3/4(c) + 1/4(0.2) = 40(0.32) 3/4(c)(1/4 (0.2)) = 40(0.32) 30(c)(10(0.2)) = 40(0.32)
A reaction is of first order for A has a rate constant of 6 per minute. If [A] =50 mol per liter, when would [A] reach the value of 0.05 mol per liter?
To solve such type of questions, you need to apply the formula of first order kinetics.ORwhere, K - Rate constant, t - time. Initially, [A] = 50 mol/litreFinal - [A] = 0.05 mol/litre, that is (a-x)On substituting the values, in the above equation we get - t = 1.15 mins
Question about Spectrophotometer?
That would be like trying to drive with a fogged up windshield. Normally, you can't see the windshield - because it doesn't interfere with the path of the light from outside before it enters your eye. But the particles (tiny water droplets) on the windshield scatter the light, resulting in a fuzzy picture for you, the driver. In a spectrometer, the sample solution is placed inside the cuvet, and a tiny spectrum light beam is shined through it. Some light is absorbed by the sample, and the rest is transmitted and hits the (also tiny) detector on the other side of the cuvet. The "absorbance" is basically the difference between the full spectrum of the beam, i.e., before it passes through the sample, and the detected light, i.e., after it passes through the sample. The cuvet itself isn't supposed to absorb any light, and normally it doesn't - but if it's dirty, that's a different situation. The oil/dirt particles will scatter (change the angle of travel of), and possibly absorb, some of the light. This will give a false reading. (a) Oil & dirt in the form of fingerprints certainly won't CREATE more light for the detector to see. But it will scatter and/or absorb some of the beam's light - which means that less will reach the detector. Remember that absorbance is light that doesn't reach the detector... (b) Beer's Law states that higher absorbance means higher concentration (A = ebC). (c) Kc is the equilibrium constant, and is basically products over reactants. I'm not sure exactly what your equation will be since I don't know what the experiment is. You will answer this question based on how the concentrations of the products and reactants will appear to change based on the effect of fingerprints on absorbance from (a) and (b).
Chemistry help! Calculate the absorbance of this solution?
A = -log (T), where T is transmittance (use the fraction 0.273) if you want molar absorptivity and not absorbance, use Beer's law A=ebc , e = molar absorptivity, b = path length (1.15 cm) , c = concentration (6.5 x 10^-5 mol-L-1). use the absorbance you found above to solve for e
Estimate the molar mass of this protein.?
P = C*R*T P = osmotic pressure (atm) C = Molar concentration (mol / L) R = 0.082 atm*L/mol K T = Temperature: C = moles / liters C = (grams / Molar mass) / (liters) C = (m / M ) / V = m / (M V) Then: P = m * R * T / (M V) M = m * R * T / (P V) m = 0.375 g T = 298 K V = 0.050 L P = 3.25 / 760 = 0.004276 atm M = 0.375 * 0.082 * 298 / (0.004276 * 0.050) M = 42860 g/mol ----------------------- Solution: a) 42,900 g/mol ----------------------- Bye bye. :-)
If 10 g of ice at - 10° C is added to 50 g of water at 15° C, what is the temperature of the mixture?
You need to understand 3 concepts to solve this answer.Firstly, You have to use the principle of calorimetry (measuring heat content of a system) to get the answer for this question.The principle goes like this:heat gained by a system(ice) = heat given by a system (water).That means the heat absorbed by ice will be equal to the heat given by the water.Secondly,now since you know the principle, next step is to know the formula of heat given or taken, that isQ= m*c*(t2-t1)where,m=mass of the substancec=heat capacity of substance (ice=2.1kJ/kgK, water=4.2kJ/kgK)t2-t1=change in temperature of the substanceNow the last but not the least concept, you must know what is latent heat, you see while there is a change of state that is when solid converts to liquid or liquid to water there is no change in temperature with the absorption of heat and that value for ice to water is 336kJ/kg.So this is the process is which is gonna happen, as the ice comes in contact with water, its temperature will rise upto 0 deg celsius. At that temperature which is the melting point of ice, it converts into water without any change in temperature. After complete conversion it again absorbs heat to reach a state where the converted ice and the water are at same temperatures (thermal equillibrium).So your final formula would be:Heat given by water = heat absorbed by ice + latent heat + heat absorbed by water (melted ice)mw*cw*(tw-T) = mice*cice*(tice-0) +336 +mmw*cmw*(T-0)The only unknown here is T =mixture temperature.Hope you got the science. :)
A compound X contains a 0.25% iron by mass. The molecular mass of X is 89600 (unitless). What is the number of iron atoms per molecule of X?
Atomic mass of Iron = 56percentage of Iron = 0.25%molecular mass of X = 89600one mole of x = 89600 gm contains 89600 * 0.25/100 = 224 gm of Iron 224 gm Iron = 224/56 = 4 mole atom of ironSince 1 Mole of X contains 4 mole atom of Iron so 1 molecule of x contains 4 atoms of Iron