A mixture of Mn2, Mg*2, Zn? was analyzed as follows. The 25 mL sample was treated with 0.25 g of Hydroxylammonium chloride (a reducing agent that maintain Manganese in +2 state), ammonia buffer (pH: 10) and few drops erichrom black T indicator and then diluted to 100 ml.. It was warmed to 40 °C and titrated with 39.98 mL of 0.045 M EDTA to the blue end point. Then NaF was added to displace Mg? from EDTA complex. The liberated EDTA required 10.26 mL of standard 0.02 M Mn*2 for complex titration. After this second end point was reached, KCN was added to displace Znt2 from EDTA complex. This time the liberated EDTA required 15.47 mL of standard 0.02 M Mn*, Calculate the number mg of each metal (Mn*/ Zn2 / Mg*?) in 25 mL sample of unknown? [AM Mn: 55, Zn: 65, Mg: 24]

Nitrogen dioxide reacts with water to form nitric acid and nitrogen monoxide according to the equation: 3no2(g)+h2o(l)→2hno3(l)+no(g) part a suppose that 4.2 mol no2 and 0.50 mol h2o combine and react completely. which reactant is in excess? express your answer as a chemical formula. nothing

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.