Answer:
The Greeks called these particles atomos, meaning indivisible, and the modern word “atom” is derived from this term. Democritus proposed that different types and combinations of these particles were responsible for the various forms of matter.
Explanation:
hope it helps
For the reaction N2(g) + 3H2(g) <=> 2NH3(g),
we have two reactants combining to form a single product. This type of reaction is called a Synthesis reaction.
(Quick side note): Because this is a reversible, you could write it in the opposite direction as a decomposition reaction.
Answer:
D
Explanation:
depending on the solid the shape will not change.
First you need to work out what mass of 84g of stainless steel is nickel, and because there's 5% you can simply divide by 20, giving 4.2g
For this you can use the equation
The mass, as was worked out previously, is 4.2g
The Mr, which is found on the periodic table, is 28
Moles =
= 0.15mol
1mol = 6.023 x
atoms
So, 0.15mol = 0.15 x 6.023 x
= 9.0345 x
atoms
The balanced equation for the above neutralisation 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 reacted - 0.250 mol/L x 20.0 x 10⁻³ L = 5.00 x 10⁻³ mol
according to molar ratio of 1:2
number of HCl moles required = 2 x number of Ca(OH)₂ moles reacted
number of HCl moles = 5.00 x 10⁻³ x 2 = 10.0 x 10⁻³ mol
molarity of HCl solution - 0.250 M
there are 0.250 mol in volume of 1 L
therefore 10.0 x 10⁻³ mol in - 10.0 x 10⁻³ mol / 0.250 mol/L = 40.0 mL
40.0 mL of 0.250 M HCl is required
