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2 years ago

A 3.140 molal solution of NaCl is prepared. How many grams of NaCl are present in a sample containing 2.314 kg of water?

Chemistry

1 answer:

Mariulka [41]2 years ago

5 0

Answer:

g NaCl = 424.623 g

Explanation:

<em>C</em> NaCl = 3.140 m = 3.140 mol NaCl / Kg solvent

∴ solvent: H2O

∴ mass H2O = 2.314 Kg

mol NaCl:

⇒ mol NaCl = (3.140 mol NaCl/Kg H2O)×(2.314 Kg H2O) = 7.266 mol NaCl

∴ mm NaCl = 58.44 g/mol

⇒ g NaCl = (7.266 mol NaCl)×(58.44 g/mol) = 424.623 g NaCl

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Convert 7.8 liters of carbon tetra fluoride cfa to grams

dolphi86 [110]

To answer the question, we assume that the given compound is an ideal gas that at STP, one mole of the substance will occupy 22.4 L. From the given volume, we determine the number of moles of substance.
7.8 L / (22.4 L /mole) = 0.3482 moles of cfa
Then, we multiply this number of moles by the molar weight of cfa which is equal to 88 g/mol.
Multiplying,
weight = (0.3482 moles of cfa) x (88 g/mol) = <em>30.64 grams</em>

4 0

2 years ago

In the Acid-Base Chemistry Experiment the measurement of pH will be used to explore acid-base concepts, analyze an unknown, and

aleksley [76]

Answer

a) A solution with a hydronium molarity of 0.00045 is acidic. True

Doing the calculus of pH

$pH= -Log [H^{+}] = -Log (0.00045)$

b) pH is a way to express the hydronium concentration over a wide range. True

pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.

c) Percent K and Fe are determined by doing ion exchange then a pH titration. False

Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate

d) About 0.2M HCl is the reagent used for the pH titrations. False.

In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.

e) A Lewis base is specie that can donate a proton to an acid. False

A Lewis base is an electron pair donor.

5 0

2 years ago

How many liters of gas will be in the closed reaction flask when 36.0L of ethane (C2H6) is allowed to react with 105.0L of oxyge

Ivan

Answer:- Volume of the gas in the flask after the reaction is 156.0 L.

Solution:- The balanced equation for the combustion of ethane is:

$2C_2H_6(g)+7O_2(g)\rightarrow 4CO_2(g)+6H_2O(g)$

From the balanced equation, ethane and oxygen react in 2:7 mol ratio or 2:7 volume ratio as we are assuming ideal behavior.

Let's see if any one of them is limiting by calculating the required volume of one for the other. Let's say we calculate required volume of oxygen for given 36.0 L of ethane as:

$36.0LC_2H_6(\frac{7LO_2}{2LC_2H_6})$

= 126 L $O_2$

126 L of oxygen are required to react completely with 36.0 L of ethane but only 105.0 L of oxygen are available, It means oxygen is limiting reactant.

let's calculate the volumes of each product gas formed for 105.0 L of oxygen as:

$105.0LO_2(\frac{4LCO_2}{7L O_2})$

= 60.0 L $CO_2$

Similarly, let's calculate the volume of water vapors formed:

$105.0L O_2(\frac{6L H_2O}{7L O_2})$

= 90.0 L $H_2O$

Since ethane is present in excess, the remaining volume of it would also be present in the flask.

Let's first calculate how many liters of it were used to react with 105.0 L of oxygen and then subtract them from given volume of ethane to know it's remaining volume:

$105.0LO_2(\frac{2LC_2H_6}{7LO_2})$