Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example,
<span>in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some </span>
<span>insects (e.g. water striders) and even reptiles (basilisk) to run on the water surface. This property is caused by cohesion </span>
<span>of like molecules, and is responsible for many of the behaviors of liquids..</span>
Plz specify your answer. thank u
Answer:
227 mL KBr
Explanation:
To find the amount of milliliters KBr, you need to (1) convert grams to moles (via molar mass from values on periodic table), then (2) find the amount of liters KBr (via molarity equation using molarity and moles), and then (3) convert liters to milliliters. The final answer should have 3 sig figs to match the amount of sig figs in the given values.
<u>(Step 1)</u>
Molar Mass (KBr): 39.098 g/mol + 79.904 g/mol
Molar Mass (KBr): 119.002 g/mol
17.2 grams KBr 1 mole
----------------------- x ------------------ = 0.145 moles KBr
119.002 g
<u>(Step 2)</u>
Molarity (M) = moles / volume (L)
0.640 M = 0.145 moles / volume
(0.640 M) x (volume) = 0.145 moles
volume = (0.145 moles) / (0.640 M)
volume = 0.227 L
<u></u>
<u>(Step 3)</u>
<u></u>
0.227 L KBr 1,000 mL
------------------ x ----------------- = 227 mL KBr
1 L
The volume of O₂ : 21 L
<h3>Further explanation</h3>
Given
8.7 grams of C₂H₄
Required
Volume O₂
Solution
Reaction
C₂H₄ + 3 O₂ ⇒ 2 CO₂ + 2 H₂O
mol C₂H₄(MW= 28 g/mol) :
= mass : MW
= 8.7 g : 28 g/mol
= 0.311
From the equation, mol O₂ :
= 3/1 x mol C₂H₄
= 3/1 x 0.311
= 0.933
At STP, 1 mol gas=22.4 L, so for 0.933 mol :
= 0.933 x 22.4 L
= 20.899 L ≈ 21 L
Answer:
2.3)X10^13-Hz
Explanation:
What’s the frequency of radiation that has a wavelength of 13 um, about the size of bacterium?
a micro meter is 10^-6 meter
frequency of light times wavelength = c the speed of light 3X10^8 M/sec
so
frequency times 13 X10^-6 =3X10^8 M/
so
FR3EQUENCY = 3X10^8/13X10-6
=(30/13)10^13 =2.3)X10^13-Hz
7 X
6
