I will give BRAINIEst please!!! help meeee omg

Chemistry

1 answer:

Alexxandr [17]3 years ago

4 0

Answer:

(a)57.48 percent (b) 29.45 percent

Explanation:

copper(II) bromide is 29.45 percent copper and 71.54 percent bromine. so the first element percentage composition is always the percentage composition of the compound.

that goes same with sodium hydroxide. it is 57.48 percent sodium, 40 percent oxygen, and 2.52 percent hydrogen.

You might be interested in

The decomposition of NI3 to form N2 and I2 releases −290.0 kJ of energy. The reaction can be represented as 2NI3(s)→N2(g)+3I2(g)

EastWind [94]

Answer:

-7.34 kilo Joules is the change in enthaply when 20.0 grams of nitrogen triiodide decomposes.

Explanation:

Mass of nitrogen triiodide = 20.0 g

Moles of nitrogen triiodide = $\frac{20.0 g}{395 g/mol}=0.05063 mol$

$2NI_3(s)\rightarrow N_2(g)+3I_2(g), \Delta H_{rxn}=-290.0 kJ$

According to reaction, 2 moles of nitrogen triiodide gives 290.0 kilo Joules of heat on decomposition ,then 0.05063 moles of nitrogen triiodide will give :

$\frac{-290.0 kJ}{2}\times 0.05063=-7.34 kJ$