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3 years ago

Which products might be developed based on van der waals forces

1 answer:

8 0

One of the amazing products that have been developed under Van Der Waals forces is the suction cup that is used as an ankle and is used by workers as a safety gear on cleaning or constructing high-rise buildings.
Like geckos, they can scamper up walls, scuttle along ceilings and hang upside down on polished glass surfaces.

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HELP! PLEASE! ASAP! Manganese(III) fluoride, MnF3, can be prepared by the following reaction:

Crank

Answer:

14.336 g MnF₂

Explanation:

number of moles = mass / molecular weight

number of moles of MnI₂ = 55 / 309 = 0.178 moles

number of moles of F₂ = 55 / 38 = 1.447 moles

From the reaction and the number of moles calculated we deduce that the fluorine F₂ is a limiting reactant.

So:

if 13 moles of F₂ reacts to produce 2 moles of MnF₃

then 1.447 moles of F₂ reacts to produce X moles of MnF₃

X = (1.447 × 2) / 13 = 0.223 moles of MnF₃ (100% yield)

For 57.2% yield we have:

number of moles of MnF₃ = (57.2 / 100) × 0.223 = 0.128 moles

mass = number of moles × molecular weight

mass of MnF₃ = 0.128 × 112 = 14.336 g

3 0

3 years ago

What is the answer to this? i do give brainliest to the first person who responds!!!!!

IrinaVladis [17]

Answer: the moon passes through the earth's shadow

Explanation:

In this case the earth's shadow blocks the sun's light which normally is reflected off the moon's surface. So since the sunlight is blocked by the earth we call this a lunar eclipse

4 0

3 years ago

2.70g of Zn (s) reacts with 50.0 mL of 1.00 M HCl solution to produce hydrogen gas according to the reaction. (R = 0.08206 L·atm

Anika [276]

Answer:

a. 0.0413 moles Zn

b. 0.0500 moles HCl

c. HCl is the limiting reactant

d. 0.0250 moles H₂

e. V = 0.56L

Explanation:

The reaction of Zn(s) with HCl is:

Zn(s) + 2HCl (aq) → ZnCl₂ (aq) + H₂(g)

Where 1 mole of Zn reacts with 2 moles of HCl.

a) To convert mass in grams to moles of a substance you need to use molar mass (Molar mass Zn: 65.38g/mol), thus:

2.70g Zn × (1mol / 65.38g) = 0.0413moles of Zn

b. Now, when you have a solution in molarity (Moles / L), you can know the moles of a volume of solution, thus:

Moles HCl:

50.0mL = 0.0500L × (1.00mol / L) = 0.0500 moles HCl

c. The limiting reactant is founded by using the chemical reaction as follows:

For a complete reaction of 0.0500 moles HCl you need:

0.0500 moles HCl × (1 mole Zn / 2 moles HCl) = 0.0250 moles Zn

As you have 0.0413 moles of Zn, and you need just 0.0250 moles for the complete reaction, Zn is the exces reactant and HCl is the limiting reactant

d.As HCl is limiting reactant and 2 moles of HCl react with 1 mole of H₂, moles of hydrogen formed are:

0.0500 moles HCl × (1 mole H₂ / 2 moles HCl) = 0.0250 moles H₂

e. Using PV = nRT, you can find volume of gas, thus:

PV = nRT

V = nRT / P

Where P is pressure 1atm at STP, n are moles, R is gas consant 0.08206Latm/molK and T is absolute temperature 273.15K at STP.

V = 0.0250molesₓ0.082atmL/molKₓ273.15K / 1atm

V = 0.56L

3 0

3 years ago

Calculate the molarity of the NaCl solution when 43.8 g of NaCl is dissolved in 100 mL of water.

Ad libitum [116K]

Answer: The molarity of solution is 7.45 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in ml

moles of $NaCl$ = $\frac{\text {given mass}}{\text {Molar mass}}=\frac{43.8g}{58.5g/mol}=0.745mol$

Now put all the given values in the formula of molality, we get

$Molarity=\frac{0.745\times 1000}{100}$

$Molarity=7.45M$

Therefore, the molarity of solution is 7.45 M

7 0

3 years ago

Marshall determines that a gas has a gauge pressure of 276 kpa what's the absolute pressure of the gas

omeli [17]

A gauge records the pressure over atmospheric pressure (0kpa on the gauge is actually the atmospheric pressure and a reading of 276kpa is 276kpa over atmospheric pressure). That means that means that to find absolute pressure you just add atmospheric pressure (around 1atm (101kpa)) to 286kpa to get 387kpa. I hope this helps.

6 0

4 years ago