by bouncing it
Explanation:
when you bouce a ball it hits the ground because gravity pulls it down
pls help 8th grade k12
if you are a scientific or a inventor what do you want to discover or to invent relate to electrogmagnetism
Answer:
Michal Faraday 19th century
1: Given that Ka for HCOOH is 1.8×10^-4 at 25°C what is the value of b for COOH− at 25 °C?
Kb=
2: Given that b for (CH3)2 NH is 5.4×10^-4 at 25°C, what is the value of Ka for (CH3)2NH+2 at 25 °C?
Ka=
Explanation:
At 25 °C Dissociation constant of water or Kw = 1× 10^-14 mol2dm-6
Ka × Kb = Kw for all diluted solutions
Ka×Kb = 1 × 10^-14 mol2dm-6
Therefore for question 1 -
COOH- is the conjugate base for HCOOH ( we find the conjugate base by removing an H atom and the Conjugate acid by adding an H atom)
COOH- (aq) + H2O ( l) <-----> HCOOH( aq) + OH-(aq)
So we can apply the above mentioned equation to find Kb value for COOH-
Kb = 5.56 × 10^-11 moldm-3
For question 2-
We can see that (CH3)2NH+2 is the conjugate acid of (CH3)2 NH. (A H atom has been removed so the one with a H atom less is the conjugate base.)
(CH3)2NH+2 (aq) + H2O (l) <-----> (CH3)2 NH (aq) + H3O+ (aq)
So applying the previously mentioned equation we get Ka = 1.85 × 10^-11 moldm-3
Someone please help me :)))
Answer:
3. solids are measured in centimeters
4. gases And liquids are measured in milliliters
Answer:
Solids are measured in Mass
Gases and Liquids are measured in Volume
Explanation:
Solids can also additionally be measured by length as well.
fun fact: natural gas is measured by volume (cubic feet) but is sold based on its heating content (Btus). A cubic foot of natural gas is the amount of natural gas that can be contained in a cube one foot on a side, at a certain standard temperature and pressure. (source; oilgaslawyer blog)
Describe your observations when the paper clip was gently crushed with the pestle
Answer:
We can do an experiment with vinegar to see what happens to the calcium in an eggshell when it is exposed to an acid.
Hello can someone please help me. Me and my mom went to the doctor and the doctor told me I can’t have sex till 19 because of my health problems. But they didn’t tell me what health problems! Can someone tell us there any health things or a name for that?
Answer:
bladder or bowel diseases, or arthritis. These might be your answer.
The result of a division problem is the a ) divisor . b ) quotient . c ) factor . d ) remainder .
Answer:
The number by which we divide is called the divisor. The result obtained is called the quotient. The number left over is called the remainder.
Explanation:
A balloon with an initial volume of 3.1 L at a temperature of 193 K is warmed to 374 K.
What is its volume at the final temperature? (Assume constant temperature.)
Answer:
New volume = 6.0L
Explanation:
Make a list of variables given in the question, and what we want to find:
Initial volume (L) = Vi = 3.1
Initial temperature (K) = Ti = 193
New temperature (K) = Tn = 374
New volume (L) = Vn
We have volumes and temperatures given and we're talking about gas, the equation including both these variables that should come to mind is the ideal gas equation:
PV = nRT
P = pressure (Pa)
n = number of moles
R = gas constant = 8.31
Now, we construct an equation we can solve to get the new volume:
P(Vn) = nR(Tn)
And insert the values we know:
P(Vn) = n(8.31)(374)
P(Vn) = n·3107.94
The equation contains 3 unknown variables;
We should first try to see if we can eliminate the 2 we are not interested in, namely P and n;
What we should recognise is that the pressure and number of moles will not change upon warming the balloon;
Firstly, heating the gas inside the balloon doesn't add anything to the balloon, i.e. doesn't increase the moles of gas, it simply raises the energy of the gas particles already within the balloon, so n will not change;
Secondly, I think there is a mistake in the question, it should read "assume constant pressure" in the brackets, since the temperature does change, which we are told;
Also, we can assume normal atmospheric pressure inside and outside the balloon as would be the case ordinarily;
What we want to do with this information is rearrange the equation we constructed to have these 2 constant or unchanging variables on one side and everything else on the other, so:
[tex]\frac{P}{n} = \frac{3107.94}{V_{n} }[/tex]
Next, we construct an equation for the balloon before warming:
P(Vi) = nR(Ti)
P(3.1) = n(8.31)(193)
P·3.1 = n·1603.83
Once again, rearrange to get P and n on one side of the equation and everything else on the other:
[tex]\frac{P}{n} = \frac{1603.83}{3.1} \\\\ \frac{P}{n} = 517.364516[/tex]
Now, we have two equations for P/n, we can eliminate P/n since both these values remain the same before and after warming the balloon as previously established:
[tex]\frac{3107.94}{V_{n} } = \frac{P}{n} = 517.364516 \\\\ \frac{3107.94}{V_{n} } = 517.364516 \\\\[/tex]
Now, rearrange and solve for Vn:
[tex]\frac{3107.94}{V_{n} } = 517.364516 \\\\ V_{n} = \frac{3107.94}{517.364516} \\\\ V_{n} = 6.00725...[/tex]
Vn = 6.0L
true or false, Electromagnetic radiation with a higher energy, travels with higher speed than electromagnetic radiation with a lower energy
Answer:
True.
Explanation:
Since electromagnetic radiation travels in waves, we can assume that the more high energy the waves are, the faster they will go. So therefore, higher energy travels faster.
Hope that helps you!
Answer:
True
Explanation:
Are the 3 right for number 12?
2. Why do you think electroplated jewelleries are in demand?
Chemistry plsss
Explanation:
Electroplated jeweleries are in demand because firstly they are as shiny and attractive as real jeweleries, they are also light weighted and cost effective.
One night a student notices that one-quarter of the moon is visible. What is the likely explanation for this view?
If a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
Eclipse is said to occur when one of the heavenly bodies casts a shadow on another heavenly body causing it to be partly visible or completely invisible. When the earth comes between the sun and the moon, a lunar eclipse is said to occur.
When a lunar eclipse occurs, the moon may be partly visible or completely invisible. Therefore, if a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
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Suppose you have samples of three unknown solids. Explain how you could use their properties to
determine whether or not they are ionic solids.
Using melting and boiling temperature, hardness and electric current passing testing.
Ionic solidsIonic solids are materials that have a strong bond between their ions, thus producing well-defined shapes.
In addition, due to this strong attraction, the boiling and melting temperatures of these materials are very high, in addition to the resistance to breakage presented by them.
Finally, ionic solids are also excellent conductors of electricity.
So, their properties used to determine whether or not they are ionic solids are melting and boiling temperature, hardness and electric current passing testing.
Learn more about ionic solids: brainly.com/question/8236583
How many carbon dioxide molecules and water molecules are needed to make one molecule of glucose?
Answer:
It takes six molecules of carbon dioxide and six molecules of water to make one molecule of glucose.
Sodium hydroxide neutralises hydrochloric acid as shown in the equation:
NaOH(aq) + HCl(aq) i NaCl(aq) + H2O(l)
(4)
dm3
(3)
The student found that 27.20 cm3 of 0.100 moles per dm3 sodium hydroxide neutralised 5.00 cm3 of hydrochloric acid.
Calculate the concentration of the hydrochloric acid in moles per dm3.
Give your answer to three significant figures.
Explanation:
Mole ratio of NaOH : HCl = 1: 1
Moles of NaOH used = 0.1 mol/1000 cm3 × 27.20 cm3
= 2.72 × 10^-3 mol
Therefore moles of HCl used is also 2.72 × 10^-3 mol
So concentration of HCl can be found by dividing the no.of moles of HCl by the volume of HCl as follows
2.72 × 10^-3 mol/ 5cm3
1000cm3 = 1dm3
Therefore,
1cm3 = 1/1000 dm3
5cm3 = 5/1000 dm3
HCl conc. = 2.72 × 10^-3 mol/ 5×10^-3 dm3
= 0.544 moldm-3
How many double bonds does CCL2H2 have?
A chemical property is a change in _____.
density
physical state
hardness
composition of matter
Answer:
composition of an element
Grace wanted to find out the best conditions for growing lettuce plants.
She took 4 trays and planted 8 lettuce plants in each.
The results of her investigation are shown below.
How many days did the investigation last?
Use the table to help you.
Explanation:
the investigation lasts for 7 days !
hope this helps you.
Magnesium metal burns in air with an intense bright light according to the equation
2 Mg(s) + O2(g) → 2 MgO(s) + 1200 kJ
A.) What is the amount of energy in kJ produced when 4.5 mol of Mg is burned in the presence of excess oxygen?
The heat produced by 4.5 moles of magnesium when burnt is 2700 kJ.
A thermochemical reaction is a reaction in which the amount of heat lost or gained is included in the reaction equation. The thermochemical reaction equation for the combustion of magnesium is shown as follows;
2 Mg(s) + O2(g) → 2 MgO(s) + 1200 kJ
From the reaction equation;
2 moles of magnesium produced 1200 kJ of heat
4.5 moles of magnesium will produce 4.5 moles × 1200 kJ/2 moles
= 2700 kJ
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he hybridization of carbon in diamond is _________. Enter your answer with no superscripts or subscripts, i.e., ab3.
Diamond is composed of hexagonal rings in which sp3 hybridized carbon atoms are linked together.
Hybridization refers to the mixing of atomic orbitals to yield hybrid orbitals that are suitable for bonding. The energy of orbitals that combine to form hybrid orbitals must be close enough for such combination to take place.
Diamond is composed of hexagonal rings in which sp3 hbridized carbon atoms are linked together. Each carbon atom in diamond is tetrahedral.
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The mixing of the two different orbitals to form a compound is called hybridization. For example mixing of s and p orbits.
The correct answer is sp3.
The arrangement of the elements in a different manner to form a new compound is called allotropes. For example, diamond and graphite are the allotropes of carbon.
The valence electrons are in p orbitals and p orbit mixed after the s orbitals.
Therefore, the correct answer is sp3
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The melting point of H₂O(s) is 0 °C. Would you expect the melting point of H₂S(s) to be 85 °C, 0 °C or -85 °C.? Justify your choice
Answer:
-85 °C
Explanation:
O and S are in the same group( Group 16). Since S is below O it's atomic mass is higher than O. So molar mass of H2S is higher than H2O. The strength of Vanderwaal Interactions ( London dispersion forces) increases when the molar mass increases. However, only H2O can form H bonds with each other. This is because electronegativity of O is higher than S and therefore H in H2O has a higher partial positive charge than H of H2S.
H bond dominate among these 2 types of forces so the strength of attractions between molecules is higher in H2O than H2S. Therefore more energy should be supplied for H2O to break inter
molecular forces and convert from solid to liquid state than H2S. So mpt of H2O must be higher than that of H2S.
Escriba un poema usando 4 de las siguientes palabras: lluvia, nieve, lluvia, granizo, tornado, huracanes, frente cálido, frente frío, alta presión, baja presión, termómetro, barómetro, anemómetro, pluviómetro, veleta o higrómetro.
plis ayúdenme porfa
Answer:
i dont speak mexican
Explanation:
Which which characteristics determines color? A. The Measurement from crest crest. B. The highest point on the wave. C. The lowest points on the waves D. The number of waves that pass per second. Please give me a good response.
Answer:
The answer is option A
Explanation:
This is because the measure from crest to crest is also known as the wavelength, and the color of a wave always depends on its wavelength, if you see the electromagnetic spectrum
Hope this helps!
Chemical properties of mercury hg
Answer:
Mercury has a relatively high vapour pressure and the highest volatility of any metal, vapourizing to become a colourless, odourless gas. The metal is a fair conductor of electricity, but a poor conductor of heat. Mercury's atomic number is 8.
Commercially prepared cloning vectors such as pUC18 are designed to contain several useful features. An example of one of these features is ________.
Vectors may be plasmids. An example of one of several useful features of commercially prepared cloning vectors is MULTIPLE CLONING SITES.
The pUC18 vector is a widely used standardized cloning vector for replication in Escherichia coli.
A multiple cloning site can be defined as a short DNA fragment observed in genetically engineered plasmids.
These DNA fragments (multiple cloning sites) contain twenty (20) or more sites where restriction enzymes can cut in order to generate recombinant DNA molecules.
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A hydrochloric acid solution is standardized by titrating 0.2329 g of primary standard sodium carbonate to a methyl red end point by boiling the carbonate solution near the end point to remove carbon dioxide. If 42.87 mL acid is required for the titration, what is its molarity
HELP
The molarity of the acid, HCl solution is 0.103 M
We'll begin by calculating the number of mole in 0.2329 g of Na₂CO₃
Mass of Na₂CO₃ = 0.2329 g
Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3) = 106 g/mol
Mole of Na₂CO₃ =?Mole = mass / molar mass
Mole of Na₂CO₃ = 0.2329 / 106
Mole of Na₂CO₃ = 0.0022 mole Next, we shall determine the number of mole of HCl needed to react with 0.0022 mole of Na₂CO₃Na₂CO₃ + 2HCl —> 2NaCl + H₂O + CO₂
From the balanced equation above,
1 mole of Na₂CO₃ reacted with 2 moles of HCl.
Therefore,
0.0022 mole of Na₂CO₃ will react with = 0.0022 × 2 = 0.0044 mole of HCl
Finally, we shall determine the molarity of the HCl.Mole of HCl = 0.0044 mole
Volume = 42.87 mL = 42.87 / 1000 = 0.04287 L
Molarity of HCl =?Molarity = mole / Volume
Molarity of HCl = 0.0044 / 0.04287
Molarity of HCl = 0.103 MThus, the molarity of the acid, HCl solution is 0.103 M
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The table shows the order of the Sun and some of the planets in our solar system.
The letters represent the Earth, Neptune and the Sun, so match them up in your answer.
Explanation:
A=Sun
B=Earth
C=Neptune.
hope my answer will definitely help you out.
Oil does not dissolve in water because
Explanation:
Oils are made up of long hydrocarbon chains which are non polar. Since water is a polar solvent oil doesn't dissolve in water well.( Polar solutes dissolve in polar solvents and non polar solutes dissolve in non polar solvents) The hydrocarbon chains are hydrophobic.
Jackson uses a battery operated toothbrush that is rechargeable. what happens when Jackson plugs in his toothbrush into an electrical outlet to recharge it ?
A. chemical energy is transformed to sound energy.
B. electrical energy is transformed to kinetic energy.
C. chemical energy is transformed to kinetic energy.
D. electrical energy is transformed to chemical energy
Answer:
the answer would be B
Explanation:
The power from the charger use electricity and the electricity transforms to energy that can be moved
Based on the diagram, describe the atomic structure of phosphorus. Be sure to include in your answer how many electron levels, protons, neutrons, valence electrons, and electrons are present in a neutral phosphorus atom.