The answer is 8.13 x 10²⁸ atoms.
First
we calculate the number of moles using
the molar mass.
molar mass of helium = <span>4 g/mol. </span>
<span>
it means that 1 mole of helium atoms weighs 4 gram.</span>
Now we have 540 kg of helium =540000 grams
Number
of moles in 540000 grams;
540000 / 4 =135000 mol
Now in one mole there is 6.02 x 10²³ atoms
So, in 135000 mol there is;
135000 x 6.02 x 10²³ = 8.13 x 10²⁸atoms
The balanced chemical equation for the above reaction is as follows ;
Ca(OH)2 + 2HCl —> CaCl2 + 2H2O
Stoichiometry of Ca(OH)2 to HCl is 1:2
Number of Ca(OH)2 moles present - 0.001 mol/L / 1000 mL/L x 25 mL
Number of Ca(OH)2 moles = 2.5 x 10^(-5) mol
Number of HCl moles needed for neutralisation = 2.5 x 10^(-5) mol x2 = 5 x 10 ^(-5) mol
The molarity of HCl solution is 0.005 M
The solution contains 0.005 mol in 1000 mL
Therefore volume of 5x10^(-5) mol in = 1000/0.005 x 5 x 10^(-5) mol = 10 mL
10 mL of HCl is needed for neutralisation
The production of plastics makes life <span> ⇒ easier</span><span>, so it benefits society. On the other hand, the production of plastics causes air and water </span><span> ⇒ pollution</span><span>, so it also harms society.</span>
36% amount of radiolabeled proline can be expected in the translated polypeptides if a cell-free translation experiment like Nirenberg and Matthaei is performed.
<h3 /><h3>
What do you mean by Radiolabeling? </h3>
Any combination of radioactive material and a chemical. A common technique in pharmaceutical research and development for tracking specific molecules and compounds is radiolabeling. It resembles carbon dating, a more well-known method for determining the age of organic substances based on how quickly carbon decomposes. Additionally, radiolabeling is a method used to follow a radioisotope-containing molecule as it moves through a biological system, metabolic pathway, cell, tissue, or organism. Specific atoms are "tagged" by substituting their isotopes in the reactant.
To learn more about Radiolabeling, visit:
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Strong electron withdrawing groups prevents Friedel Crafts reaction because when a withdrawing group attracts the electrons decrease the availability of the electronic pair and the enough electronic density of it in order to make possible the aromatic electrophilic substitution.
Strong electron donating groups like NH2 doesn’t undergo Friedel Crafts reaction because NH2 is a Lewis base that means an electron donor. Due to Friedel Crafts reaction is an acid base reaction, the AlCl3 will be attacked by the lone pair available from NH2 producing a salt. The same occurs with phenol because the lone pair of electrons available in the OH group so Friedels Crafts doesn’t undergo with benzene attached to the strong electron donating groups NH2 or OH.