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2 years ago

Answers for both boxes please

Chemistry

1 answer:

Elan Coil [88]2 years ago

3 0

Explanation:

$\frac{6.900 \times {10}^{10} }{4.000 \times {10}^{8} } \\ 1.725 \times {10}^{10 - 8} \\ 1.725 \times {10}^{2}$

Hope it will help you :)

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What is the concentration of no3- ions in a solution prepared by dissolving 15.0 g of ca(no3)2 in enough water to produce 300. m

r-ruslan [8.4K]

Ca(NO3)2 -------> Ca²⁺ +2NO3⁻

M(Ca(NO3)2)= M(Ca) + M(N) + 6M(O)= 40.0 +14.0 +6*16.0 = 150 g/mol

15.0 g Ca(NO3)2 * 1mol/150 g = 0. 100 mol Ca(NO3)2

Ca(NO3)2 -------> Ca²⁺ +2NO3⁻
1 mol 2 mol
0.100 mol 0.200 mol

We have 0.2 mol NO3⁻ in 300. mL=0.300 L of solution,
so
0.200 mol NO3⁻ / 0.300 L solution ≈ 0.667 mol NO3⁻ /L solution = 0.667 M

Concentration of NO3⁻ is 0.667 M.

4 0

3 years ago

Sodium Chloride is an ionic compound. Its molar mass is 58.44g. One formula unit of NaCl consists of one____, whose chemical sym

saul85 [17]

Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is $Na^+$ and one anion whose chemical symbol is $Cl^-$

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

The cation is formed by the metal sodium which forms $Na^+$ and the anion is formed by non metal chlorine which forms $Cl^-$ .

For a formula unit of sodium chloride, the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus

$Na^+$ and $Cl^-$ combine to form neutral $NaCl$

5 0

2 years ago

A student heats 10.52 g of sodium hydrogen carbonate in a crucible until the compound completely decomposes to sodium carbonate

saveliy_v [14]

Answer:

$m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3$

Explanation:

Hello!

In this case, since the decomposition of sodium hydrogen carbonate is:

$2NaHCO_3(s)\rightarrow Na_2CO_3(s)+H_2O(g)+CO_2(g)$

Thus, since there is a 2:1 mole ratio between the sodium hydrogen carbonate and sodium carbonate, and the molar masses are 84.01 and 105.99 g/mol respectively, we obtain the following theoretical yield:

$m_{Na_2CO_3}^{theoretical}=10.52gNaHCO_3*\frac{1molNaHCO_3}{84.01gNaHCO_3}*\frac{1molNa_2CO_3}{2molNaHCO_3} *\frac{105.99gNa_2CO_3}{1molNa_2CO_3}\\\\ m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3$

Best regards!

4 0

3 years ago

Which is an example of a polymer?

g100num [7]

Answer:

diamond

Explanation:

5 0

2 years ago

If a liquid sample of naphthalene is heated and remains at 218 degrees c until it is completely vaporized, you know that 218 deg

Alexxandr [17]

<span>The correct answer is b. Boiling point, why? because the liquid sample of napthalene is heated and remained at the temperature of 218 degrees celsius, the outcome was that the napthalene was completely vaporized, therefore we are given the scenario that at the temperature of 218 degrees celsius is considered to be the boiling pont of napthalene.</span>

5 0

3 years ago

Read 2 more answers

Answers for both boxes please ​

Answers for both boxes please