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Some metal chips with a total volume of 3.29 cm3 are placed on a piece of paper and weighed. The combined mass is found to be 18.43 g, and the paper itself weighs 1.2140 g. Calculate the density of the metal to the proper number of significant figures.
in which of the following substances there is a greater number of moles?
Ca=40 Na=23 He=4 Mg=24 Li=7
A. 5g of Ca
B. 2g of Na
C. 10g of He
D. 25g of Mg
E. 15g of Li
Why does the size of a hydrode ion varies with the metal ion to which it is bound?
I take 5g of solid-liquid mixture sample,after acid digestion and make up to 50ml,from which I take 10 ml for chloride analysis,there 0.2ml AgNO3 consumed after back titration against 0.02N AgNO3 and NH4SCN.
how to calculate the chloride in the original sample? unit of result as mg/L or mg/kg?
if the molar mass of H2SO4 is 98.09 g/mol . how many grams of H2SO4 are in one mole of this substance?when 2.76 g (0.02 mol) of kco was added to 30,0 cm3 of app 2 mol dm-3 HCl the temperature rose by 5.2 degrees celcius. write a balanced equation, calculate the enthalpy change of this reaction per mole of k2co3. the specific heat capacities of solution are 4.2Jg-1k-1 and all solutions have a density of 1.0 gcm-3
Tarnishing of silver is caused by small amounts of hydrogen sulfide released into the atmosphere by decaying organic material and volcanic activity. According to the following equation:
4Ag(s) + 2H2S(g) + O2(g) → 2Ag2S(s) + 2H2(l)
How many grams of Ag2S can be produced from 1.70g H2S if sufficient amount of the other reactants are present?
A sample, KOH, K2CO3, dissolved in water (35cm3). Its solution was titrated with 1.058moldm-3 HCl requiring 17.7cm3 to make it colourless due to phenolphthalein solution. After adding methyl orange, the solution consumed further 6cm3 of the acid to complete the neutralisation. What is the concentration of the sample?
An alkaline sample of sodium compounds (NaOH, Na2CO3) was dissolved in water 25cm3, was titrated with 1.058moldm-3 H2SO4 at 6.8cm3 to make it the solution colourless after phenolphthalein was added. After adding methyl orange a further 16.5cm3 more of the acid were needed to complete the analysis. What is the concentration of both?
