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3 years ago

List in order which digits are significant in the following numbers:

Chemistry

1 answer:

ozzi3 years ago

5 0

Answer: see below

<u>Explanation:</u>

Zeros between the digit and decimal point are NOT significant.

Zeros between digits ARE significant.

a. 230 mL. sf: 23

b. 0.00540 s sf: 540

c. 1440 sf: 144

d. 50 ℃ sf: 5

e. 0.9405 g/cm3 sf: 9405

f. 700 jellybeans sf: 7

g. 1.05 x 10⁶ sf: 105

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According to a label on a bottle of concentrated hydrochloric acid, the contents are 36.0% HCl by mass and have a density of 1.1

snow_lady [41]

Answer:

1) 11.64 mol/L is the molarity of concentrated HCl.

2) 135.40 mL of volume of 11.64 M will need to prepare 985 mL of 1.6 M HCl.

3) 1,711.08 grams of sodium bicarbonate would be needed to neutralize the spill HCl solution.

Explanation:

HCl solution with 36.0% HCl by mass, menas that in 100 g of solution 36.0 gram of HCl is present.

Mass of HCl= 36.0 g

Moles of HCl = $\frac{36.0 g}{36.5 g/mol}=0.9863 mol$

Mass of solution ,m= 100 g

Volume of solution = V = ?

Density of the solution ,d= 1.18 g/mL

$V=\frac{d}{M}=\frac{100 g}{1.18 g/mL}=84.75 mL=0.08475 L$

$Molarity=\frac{Moles }{\text{Volume of solution (L)}}$

Molarity of the solution :

$=\frac{0.9863 mol}{0.8475 L}=11.64 mol/L$

11.64 mol/L is the molarity of concentrated HCl.

$M_1V_1=M_2V_2$ ( Dilution equation)

$M_1= 11.64 M$

$V_1=?$

$M_2=1.6 M$

$V_2=985 mL$

$V_1=\frac{M_2V_2}{M_1}=\frac{1.6 M\times 985 mL}{11.64 M}$

$=135.40 mL$

135.40 mL of volume of 11.64 M will need to prepare 985 mL of 1.6 M HCl.

$NaHCO_3+HCl\rightarrow NaCl+H_2O+CO_2$

Concentration of HCl solution = 11.64 M

Volume of the HCl solution = 1.75 L

Moles of HCl in 1.75 L solution = n

$11.64 M=\frac{n}{1.75 L}$

$n=1.75 L\times 11.64 M=20.37 mol$

According to reaction 1 mole of HCl neutralized by 1 mole of sodium carbonate.

Then 20.37 moles of HCl will neutralized by ;

$\frac{1}{1}\times 20.37 mol=20.37 mol$ of sodium carbonate

Mass of 20.37 moles of sodium carbonate :

= 20.37 mol × 84g/mol = 1,711.08 g

1,711.08 grams of sodium bicarbonate would be needed to neutralize the spill HCl solution.

7 0

3 years ago

What is the rate for the second order reaction Products when [A] = 0.371 M? (k = 0.761 M's")

AlekseyPX

Given :

Concentration of product [A] = 0.371 M .

Rate constant , $R = 0.761\ M^{-1}t^{-1}$ .

To Find :

The rate for the reaction .

Solution :

We know , for second order reaction , rate is given by :

$r=k[A]^2\\\\r=0.761\times 0.371^2\ M/t\\\\r=0.10\ M/t$

Therefore , the rate for the second order reaction is 0.1 M/t .

Hence , this is the required solution .

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4 years ago

How do scientists measure the idea of time so long ago?

aleksklad [387]

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3 years ago

What is the pressure in a 27.0-L cylinder filled with 44.9 g of oxygen gas at a temperature of 315 KK

steposvetlana [31]

Answer:

1.343 atm

Explanation:

We are given the following;

Pressure, p = ?

Volume v = 27 L

Mass of oxygen = 44.9 g

Temperature, T = 315 K

The formular relating all these variables is the equation;

PV = nRT

where R = gas constant = 0.08206 L atm / mole K

To obtain n, we use;

number of moles, n = Mass / molar mass = 44.9 / 32 = 1.403 moles

From the ideal gas equation;

P = nRT / V

P = 1.403 * 0.08206 * 315 / 27

P = 36.27 / 27 = 1.343 atm

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Igoryamba

Answer:

In the center is the eye, with nearly clear skies, surrounded by the violent eyewall, with the strongest winds and very heavy rain.

Explanation:

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