What is the relationship between a compound and the elements it is made from?

1 answer:

6 0

<span>The compound may have properties that are very different from those of the elements it is composed from.</span>

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How many moles of hcl are produced from a reaction with 6.2 moles of h2 given the following equation

Bas_tet [7]

It would be 12.4 moles of HCL because you multiply 6.2 by how many moles of HCL in te equation then divide it by how many moles of h2 in the equation so you multiple 6.2 by 2 moles because there’s two moles of HCL which gives you 12.4 then you divide it by one because in the equation there is only 1 mole of H2

5 0

2 years ago

EXTRA POINTSSS 1. A solution at 25 degrees Celsius is 1.0 × 10–5 M H3O+. What is the concentration of OH– in this solution?

AlekseyPX

Answer:

Concentration of OH⁻:

1.0 × 10⁻⁹ M.

Explanation:

The following equilibrium goes on in aqueous solutions:

$\text{H}_2\text{O}\;(l)\rightleftharpoons \text{H}^{+}\;(aq) + \text{OH}^{-}\;(aq)$ .

The equilibrium constant for this reaction is called the self-ionization constant of water:

$K_w = [\text{H}^{+}]\cdot[\text{OH}^{-}]$ .

Note that water isn't part of this constant.

The value of $K_w$ at 25 °C is $10^{-14}$ . How to memorize this value?

The pH of pure water at 25 °C is 7.
$[\text{H}^{+}] = 10^{-\text{pH}} = 10^{-7}\;\text{mol}\cdot\text{dm}^{-3}$
However, $[\text{OH}^{-}] = [\text{H}^{+}]=10^{-7}\;\text{mol}\cdot\text{dm}^{-3}$ for pure water.
As a result, $K_w = [\text{H}^{+}] \cdot[\text{OH}^{-}] = (10^{-7})^{2} = 10^{-14}$ at 25 °C.