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LUCKY_DIMON [66]

3 years ago

14

What element is represented by the electron configuration [ar]4s23d8?

1 answer:

beks73 [17]3 years ago

6 0

The answer is Copper

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NaOH(aq) is transferred into a test tube. CaCl2(aq) is added to the tube. What is the formula for the precipitate (if any) that

Ilya [14]

Answer:

2NaOH (aq) + CaCl2 (aq) -> 2NaCl(aq) + Ca(OH)2(s)

Formula of precipitate: Ca(OH)2 <em>(s)</em>

Explanation:

First, we do the double replacement reaction to determine our chemical equation between the reactants and products. Once we have our products, with a solubility chart (I added one below) we can determine which of the products is soluble or insoluble.

In this case NaCl is soluble or aqueous (meaning it can dissolve in water) and Ca(OH)2 is insoluble (meaning that when the reactions takes place, these two will form a solid/precipitate)

6 0

1 year ago

Given that the molar mass of NaCl is 58.44 g/mol, what is the molarity of a solution that contains 87.75 g of NaCl in 500. mL of

Stells [14]

<u>Given information:</u>

Mass of NaCl (m) = 87.75 g

Volume of solution (V) = 500 ml = 0.5 L

Molar mass of NaCl (M) = 58.44 g/mol

<u>To determine:</u>

The molarity of NaCl solution

<u>Explanation:</u>

Molarity is defined as the number of moles of solute(n) dissolved per liter of solution (V)

i.e. M = moles of solute/liters of solution = n/V

Moles of solute (n) = mass of solute (m)/molar mass (M)

moles of NaCl = 87.75 g/58.55 g.mol-1 = 1.499 moles

Therefore,

Molarity of NaCl = 1.499 moles/0.5 L = 2.998 moles/lit ≅ 3 M

<u>Ans: (D)</u>

4 0

3 years ago

Read 2 more answers

A balloon contains 2.0 L of air at 101.5 kPa . You squeeze the balloon to a volume of 0.25 L.

8_murik_8 [283]

<h3>Answer:</h3>

812 kPa

<h3>Explanation:</h3>

According to Boyle's law pressure and volume of a fixed mass are inversely proportional at constant absolute temperature.

Mathematically, $P\alpha \frac{1}{V}$

At varying pressure and volume;

P1V1=P2V2

In this case;

Initial volume, V1 = 2.0 L

Initial pressure, P1 = 101.5 kPa

Final volume, V1 = 0.25 L

We are required to determine the new pressure;

$P2=\frac{P1V1}{V2}$

Replacing the known variables with the values;

$P2=\frac{(101.5)(2.0L)}{0.25L}$

= 812 kPa

Thus, the pressure of air inside the balloon after squeezing is 812 kPa

8 0

2 years ago

What is the excess reactant in the combustion of 23 g of methane in the open atmosphere?

Marta_Voda [28]

Answer : The excess reactant in the combustion of methane in opem atmosphere is $O_{2}$ molecule.

Solution : Given,

Mass of methane = 23 g

Molar mass of methane = 16.04 g/mole

The Net balanced chemical reaction for combustion of methane is,

$CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)$

First we have to calculate the moles of methane.

$\text{ Moles of methane}=\frac{\text{ Given mass of methane}}{\text{ Molar mass of methane}}$ = $\frac{23g}{16.04g/mole}$ = 1.434 moles

From the above chemical reaction, we conclude that

1 mole of methane react with the 2 moles of oxygen

and 1.434 moles of methane react to give $\frac{2moles\times 1.434moles}{1moles}$ moles of oxygen

The Moles of oxygen = 2.868 moles

Now we conclude that the moles of oxygen are more than the moles of methane.

Therefore, the excess reactant in the combustion of methane in open atmosphere is $O_{2}$ molecule.

6 0

2 years ago

A kicked soccer ball<br> eventually comes<br> to rest. What<br> force causes<br> this?<br> ce

maks197457 [2]

Answer:

friction

Explanation:

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7 0

2 years ago