Balanced equation:
Ca(OH)2+H2SO4=CaSO4+2 H20<span />
Answer:
What is spectrophotometry? It is an analytic method that it use substances light absorbance property
How can this be useful in identifying drugs? It possible compare spectra and identify problem substance
Explanation:
The way substances absorb light is unique and because of that it is possible to use spectrophotometry for substances identifying. the model spectra are measured in ideal conditions, so, it is difficult ensure the same conditions and to achieve identical spectra.
I hope I have been helpful
Period number
Hope this helps!!
Answer:
(i) Change in colour (ii) Change in temperature (iii) Formation of precipitate
Explanation:
(i) Change in colour: Reaction between lead nitrate solution and potassium iodide solution. Pb(NO3)2(aq)+2KI → PbI2(s)+2KNO3(aq) In this reaction, colour changes from colourless to yellow. (ii)Change in temperature: Action of dilute sulphuric acid on zinc. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2 In this reaction, heat is evolved (iii) Formation of precipitate: Action of barium chloride on sodium sulphate. BaCl2(aq) +Na2SO4(aq) → BaSO4(s) +2NaCl(aq) BaSO4(s)
Answer:
1.32 x 10²⁴
Explanation:
Given parameters:
Volume of carbon tetrachloride = 49.3L
Unknown:
Number of atoms at STP = ?
Solution:
To solve this problem;
At STP;
1 mole of a substance occupies 22.4L ;
So;
Let us find the number of moles;
22.4L = 1 mole
49.3L will give 
= 2.2mole
So;
1 mole of substance contains 6.02 x 10²³ atoms
2.2 mole of Carbon tetrachloride = 2.2 x 6.02 x 10²³ = 1.32 x 10²⁴
