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2 years ago

11. If there are 8.24 x 1022 molecules of NaCl in a salt shaker, what is the mass of the salt?

Chemistry

1 answer:

vlada-n [284]2 years ago

6 0

Answer: 8.12 g NaCl

Explanation: Use Avogadro's number to find the number of m

moles of NaCl:

8.24x10²² molecules NaCl / 1 mole NaCl/ 6.022x10²³ molecules NaCl

= 0.14 mole NaCl

Next convert moles to grams NaCl using its molar mass;

0.14 mole NaCl x 58g NaCl / 1 mole NaCl

= 8.12 g NaCl

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Each orbit surrounding an atom is allowed _____.

Juli2301 [7.4K]

Two electrons is your answer glad to help!

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2 years ago

Read 2 more answers

Write the formulas for the following ionic compounds: (a) copper bromide (containing the Cu+ ion), (b) manganese oxide (containi

ivann1987 [24]

Answer:The formulas of ionic compounds are:

a) $CuBr$

b) $Mn_2O_3$

c) $Hg_2I_2$

d) $Mg_3(PO_4)_2$

Explanation:

Formulas for the an ionic compounds is determine by:

Criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

(a) Copper bromide :Given that it contains $Cu^+$ ion.

$Cu^++Br^-\rightarrow CuBr$

(b) Manganese oxide : Given that it contains $Mn^{3+}$ ion.

$Mn^{3+}+O^{2-}\rightarrow Mn_2O_3$

(c)Mercury iodide :Given that it contains $Hg_2^{2+}$

$Hg_2^{2+}+I^-\rightarrow Hg_2I_2$

(d) Magnesium phosphate :Given that it contains $PO_4^{3-}$

$Mg^{2+}+PO_4^{3-}\rightarrow Mg_3(PO_4)_2$

4 0

2 years ago

Acetaminophen (pictured) is a popular nonaspirin, "over-the-counter" pain reliever. what is the mass % (calculate to 4 significa

77julia77 [94]

Acetaminophen as a chemical formula of C8H9NO2. The molar masses are:

C8H9NO2 = 151.163 g/mol

C = 12 g/mol

H = 1 g/mol

N = 14 g/mol

O = 16 g/mol

TO get the mass percent, simply multiply the molar mass of each elements with the number of the element divide by the molar mass of acetaminophen, that is:

%C = [(12 * 8) / 151.163] * 100% = 63.50%

%H = [(1 * 9) / 151.163] * 100% = 5.954%

%N = [(14 * 1) / 151.163] * 100% = 9.262%

%O = [(16 * 2) / 151.163] * 100% = 21.17%

8 0

2 years ago

From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2

sashaice [31]

Answer:

From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.2kJ

ΔHf°(C2H2) = 227.4 kJ/mol

ΔHf°(H2O) = -285.8 kJ/mol and

ΔHf°(Ca(OH)2) = -985.2 kJ/mol

(Ans)

ΔHf° of CaC2 = -59.0 kJ/mol

Explanation:

CaC2(s) + 2 H2O(l) → Ca(OH)2(s) + C2H2 (g) = −127.2kJ

ΔHrxn = −127.2kJ

ΔHrxn = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - ΔHf°(CaC2)- 2ΔHf°(H2O);

ΔHf°(CaC2) = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - 2ΔHf°(H2O) – ΔHrxn

Where

ΔHf°(C2H2) = 227.4 kJ/mol

ΔHf°(H2O) = -285.8 kJ/mol and

ΔHf°(Ca(OH)2) = -985.2 kJ/mol

ΔHf°(CaC2) =227.4 - 985.2 + 2x285.8 + 127.2 = -59.0 kJ/mol

ΔHf°(CaC2) = -59.0 kJ/mol

7 0

2 years ago

What volume (ml) of a 0.2450 m koh(aq) solution is required to completely neutralize 55.25 ml of a 0.5440 m h3po4(aq) solution?

Nonamiya [84]

Answer: It depends on what came after "0.5440 M H...". If it was a monoprotic acid, like HCl, the calculation would go like this: (55.25 mL) x (0.5440 M acid) x (1 mol KOH / 1 mol acid) / (0.2450 M KOH) = 122.7 mL KOH If it was a diprotic acid, like H2SO4, like this: (55.25 mL) x (0.5440 M acid) x (2 mol KOH / 1 mol acid) / (0.2450 M KOH) = 245.4 mL KOH If it was a triprotic acid, like H3PO4, like this: (55.25 mL) x (0.5440 M acid) x (3 mol KOH / 1 mol acid) / (0.2450 M KOH) = 368.0 mL KOH

5 0

2 years ago