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4 years ago

An atom of sodium has 11 protons, 11 electrons,and 12 neutrons, what is its atomic number and mass number?

1 answer:

3 0

Example: A sodium atom contains 11 protons, so its atomic number is 11. Mass number is the total of the protons and neutrons together, and it is given the symbol A. Example: A sodium atom contains 11 protons and 12 neutrons; its mass number A is 23<span>.</span>

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¿Cuántos moles hay en 101,64 g de (NH4)²SO⁴?

Alex_Xolod [135]

10164g HK momjkjioikpllp

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3 years ago

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 1.025 g of naphthalene is burned in a bomb calorim

Serggg [28]

Answer:

$\Delta E_{rxn}$ for combustion of naphthalene is -5164 kJ/mol

Explanation:

$\Delta E_{rxn}=C_{calorimeter}\times \Delta T_{calorimeter}$

where, C refers heat capacity and $\Delta T$ refers change in temperature.

Here, $\Delta T_{calorimeter}=(32.33-24.25)^{0}\textrm{C}=8.08^{0}\textrm{C}$

So, $\Delta E_{rxn}=(5.11\frac{kJ}{^{0}\textrm{C}})\times (8.08^{0}\textrm{C})=41.3kJ$

$\Delta E_{rxn}$ is generally expressed in terms of per mole unit of reactant. Also, $\Delta E_{rxn}$ should be negative as it is an exothermic reaction (temperature increases).

Molar mass of naphthalene is 128.17 g/mol

So, 1.025 g of naphthalene = $\frac{1.025}{128.17}moles$ of naphthalene

= 0.007997 moles of naphthalene

$\Delta E_{rxn}=-\frac{41.3kJ}{0.007997mol}=-5164kJ/mol$

5 0

3 years ago

Please help thank you (15 points)

Eva8 [605]

Answer:

D. The sun has less gravitational pull on Pluto because it is farther away.

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3 years ago

What is the noble gas configuration for zirconium?

Mkey [24]

Answer:

[Kr] 4d² 5s²

Explanation:

5 0

3 years ago

Gaseous hydrogen and oxygen can be prepared in the laboratory from the decomposition of gaseous water. The equation for the reac

nata0808 [166]

Answer:

$m_{O_2}=87.2gO_2$

Explanation:

Hello.

In this case, given the chemical reaction, we can compute the grams of oxygen by using the 98.2 g of water via the 2:1 mole ratio between them, the molar mass of water that is 18.02 g/mol, the molar mass of gaseous oxygen that is 32.00 g/mol and the following stoichiometric procedure relating the given information:

$m_{O_2}=98.2gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{1molO_2}{2molH_2O}*\frac{32.00gO_2}{1molO_2} \\\\m_{O_2}=87.2gO_2$

In which the result is displayed with three significant figures because the given mass of water 98.2 g, has three significant figures too.

Best regards!

6 0

3 years ago