If you start with 5 molecules of O2 in the reaction 2Mg+O2--> 2MgO, how much Mg will you need?

List the five major pollutants in the United States

lawyer [7]

Fine particles, ground level ozone, sulfur dioxide, nitrogen dioxide, lead

6 0

3 years ago

How many moles of cf4 are there in 171g of cf4 ?

xeze [42]

1 is + 4 = to n please

5 0

3 years ago

Read 2 more answers

Describe how chemical substances are used based on their physical properties?

Lilit [14]

The answer is
Physical properties: Properties that do not change the chemical nature of matter
Chemical properties: Properties that do change tha chemical nature of matter

Examples of physical properties are: color, smell, freezing point, boiling point, melting point, infra-red spectrum, attraction (paramagnetic) or repulsion (diamagnetic) to magnets, opacity, viscosity and density. There are many more examples. Note that measuring each of these properties will not alter the basic nature of the substance.

Examples of chemical properties are: heat of combustion, reactivity with water, PH, and electromotive force.

3 0

3 years ago

Calculate the pH of: (a) 0.1M HCl; (b) 0.1M NaOH; (c) 3 X 10% M HNO3; (d) 5 X 10-10 M HCIO.; and (e) 2 x 10-8 M KOH.

Shtirlitz [24]

Answer:

(a) $pH = -Log (0.1M) = 1$

(b) $pH = -Log (10^{-13}M) = 13$

(c) $pH = -Log (3x10^{-3}M) = 2.5$

(d) $pH = -Log (4.93x10^{-10}M) = 9.3$

(e) $pH = -Log (5^{-7}M) = 6.3$

Explanation:

To calculate de pH of an acid solution the formula is:

$pH = -Log ([H^{+}]) = 1$

were [H^{+}] is the concentration of protons of the solution. Therefore it is necessary to know the concentration of the protons for every solution in order to solve the problem.

(a) and (c) are strong acids so they dissociate completely in aqueous solution. Thus, the concentration of the acid is the same as the protons.

(b) and (e) are strong bases so they dissociate completely in aqueous solution too. Thus, the concentration of the base is the same as the oxydriles. But in this case it is necessary to consider the water autoionization to calculate the protons concentration:

$K_{w} =[H^{+} ][OH^{-}]=10^{-14}$

clearing the $[H^{+} ]$

$[H^{+} ]=\frac{10^{-14}}{[OH^{-}]}$

(d) is a weak base so it is necessary to solve the equilibrium first, knowing $Ka=3.24x10^{-8}$

The reaction is $HClO$ → $H^{+} + CO^{-}$ so the equilibrium is

$Ka=3.24x10^{-8}=\frac{x^{2}}{5x10^{-8}-x}$

clearing the <em>x</em>

${x^{2}={1.62x10^{-17}-3.24x10^{-8}x}$

$x=[H^{+}]=4.93x10^{-10}$

6 0

3 years ago

Contrast the silica content of magma in quiet and explosive eruptions

klemol [59]

Magma in quiet eruptions has a low content in silica , while in explosive eruptions, it has a high Content in silica. A volcano that erupts quietly has magma that is low in silica. Low-silica magma has low viscosity and flows easily. A volcano that erupts explosively has magma that is high in silica. High-silica magma has high viscosity, making it thick and sticky, thus it flows slowly.

3 0

3 years ago