Answer:
Explanation:
Endo and Exo thermic are defined by what changes take place in the environment of the reaction.
If the temperature goes up, the reaction is giving up heat. It is Exothermic.
If the temperature goes down, the reaction requires heat. It is Endothermic.
In this case, the temperature went down. The reaction is Endothermic.
A chemist dilutes a 1. 0 mL sample of 2. 0 M KNO3 by adding water to it. If the concentration of the solution that is obtained is 0. 0080 M, what is its volume? Use M subscript i V subscript i equals M subscript f V subscript f. 125 mL 250 mL 500 mL 2,000 mL.
Answer:
We know the initial volume of the potassium nitrate solution is 1.0 mL and the initial concentration is 2.0 M, we also know that an unknown volume of water was added to the solution, which diluted our concentration down to a final value of 0.008 M. We are trying to find the final volume.
Here we can use this formula since the initial and final solutions are proportional. Before that let's define our variables.
[tex]M_1 = 2.0 M\\V_1 = \frac{1.0 mL}{1000} = 0.001 L\\M_2 = 0.008 M\\V_2 = \ ?[/tex]
[tex]M_{1}V_{1} =M_2 V_2\\[/tex]
[tex](2.0)(0.001) = (0.008)V_2\\\\\frac{(2.0)(0.001)}{0.008} = V_2\\\\V_2 = 0.25 L \ or \ (0.25 \ * \ 1000) = 250 \ mL[/tex]
Therefore you would have 0.25 L or 250 mL of your final solution.
How do covalent compounds differ from ionic compounds?
Answer:
1. Ionic bonds result from transfer of electrons, but covalent bonds are formed by sharing.
2. Ions are arranged in a three-dimensional array (like crystals). Covalently bonded substances exist as discrete molecular units.
3. Ionic compounds often dissociate into ions in solution, but covalently bonded molecules retain their molecular identity in solution.
Hope this helps :)
What does an atom's period tell us?
Select one:
a. Number of protons
b. Number of shells
c. Number of valence
electrons
d. Number of electron
Is this a male cat or female?
Explanation:
Lift the kitten's tail. The opening just under the tail is the anus. Below the anus is the genital opening which is round in males and is a vertical slit in females. In kittens of similar size, the distance between the anus and the genital opening is greater in the male than the female.
TW: use of inapropate words*
Answer:
not enough information to tell
Explanation:
One way you can tell this difference is the distance between the cat's genitals (organs seen on the outside of the body) and the anus. A male will have a much greater distance between the genitals and anus than females, 1/2 inch apart on a male kitten and over 1 inch apart on a male adult cat. However, if the two are almost adjacent on a kitten or less than 1/2 inch apart on an adult, it’s a female.
Based on the graph, what is the approximate half-life of the reaction shown below
Answer: 2.1 minutes
Explanation: Based on the graph, what is the approximate half-life of the reaction shown below
Write the chemical formulas and names for the following ionic compounds. Cobalt (III) and bromine
Answer:
CoBr2,CoBr2·6H2O,CoBr2·2H2O
Explanation:
silver has an atomic mass of 107.868 amu. silver has two common isotopes. one of the isotopes has a mass of 106.906 amu and a relative abundace of 51.881%. a. what is the % abundance of the other isotope. b. what is the mass if the other isotope.
A. The abundance of the 2nd isotope is 48.119%
B. The mass of the 2nd isotope is 108.905 amu
Let the 1st isotope be A
Let the 2nd isotope be B
A. Determination of the abundance of the 2nd isotope
Abundance of isotope A = 51.881%.
Abundance of isotope B =?Abundance of B = 100 – A
Abundance of B = 100 – 51.881
Abundance of B = 48.119%B. Determination of the mass of the 2nd isotope
Atomic mass of silver = 107.868 amu.
Mass of 1st isotope (A) = 106.906 amu
Abundance of isotope A (A%) = 51.881%.
Abundance of isotope B (B%) = 48.119%
Mass of 2nd isotope (B) =?[tex]atomic \: mass = \frac{mass \: of \:A \times \:A\%}{100} + \frac{mass \: of \:B \times \:B\%}{100} \\ \\ 107.868 = \frac{106.906\times \ \: 51.881}{100} + \frac{mass \: of \:B \times \:48.119}{100} \\ \\ 107.868 = \: 55.464 + 0.48119 \times mass \: of \:B \\ \\ collect \: like \: terms \\ \\ 0.48119 \times mass \: of \:B = 107.868 - 55.464 \\ \\ divide \: both \: side \: by \: 0.48119 \\ \\ mass \: of \:B = \frac{107.868 - 55.464 }{0.48119} \\ \\ mass \: of \:B =108.905 \: amu \\ \\ [/tex]
Therefore, the mass of the 2nd isotope is 108.905 amu
Learn more: https://brainly.com/question/7955048
Which of the following is a binary compound?
what are three physical properties with constant value
Answer: Certain physical constants (e.g., melting point, boiling point, density, refractivity, solubility) can be found in the literature for many compounds, whereas others (e.g., specific rotation) are characteristic of different groups of compounds and are known for almost all of them.
Explanation:
Zn + 2HCl —> ZnCl2 + H2
If you have 6.8 moles of zinc chloride produced, how many moles of zinc reacted?
Answer:
about 4 or 4.8
Explanation:
A diprotic acid (H2X) titrated with a solution of NaOH for 25 ml of the acid 87.42 ml of a 1.95 M solution of NaOH was required to reach the equivalent point, the concentration of the diprotic acid equals
0.14
6.8
3.4
0.29
The concentration of the diprotic acid equals 3.4 M
We'll begin by writing the balanced equation for the reaction.
H₂X + 2NaOH —> Na₂X + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂X (nA) = 1The mole ratio of the base, NaOH (nB) = 2From the question given above, the following data were obtained:
Volume of acid, H₂X (Va) = 25 mLVolume of base, NaOH (Vb) = 87.42 mLMolarity of base, Ca(OH)₂ (Mb) = 1.95 MMolarity of acid, H₂X (Ma) =?MaVa / MbVb = nA/nB
(Ma × 25) / (1.95 × 87.42) = 1/2
(Ma × 25) / 170.469 = 1/2
Cross multiply
Ma × 25 × 2 = 170.469
Ma × 50 = 170.469
Divide both side by 50
Ma = 170.469 / 50
Ma = 3.4 M
Therefore, the concentration of the acid, H₂X is 3.4 M
Learn more about titration:
https://brainly.com/question/25624144
Which of the following is a correctly balanced equation? A. NaClO3 → NaCl 3O2 B. 2HgO → 2Hg O2 C. 2ZnS O2 → 2ZnO 2SO2 D. 4CO Fe3O4 → 4CO2 Fe E. 2Fe 2Cl2 → 2FeCl3.
Answer:
yes is the anser
Explanation:
i donyt know how to be wrong
The correctly balanced equation among the options is 2HgO → 2Hg + O2.
BALANCING CHEMICAL EQUATION:Balancing a chemical equation means ensuring that the number of atoms of each element on both sides of the equation are the same in accordance to the law of conservation of mass.
To balance a chemical equation, we make use of coefficients, which are numbers placed in front of the element or compound in the reaction.
According to this question, the following equation: 2HgO → 2Hg + O2, is correctly balanced because the number of atoms of Hg (2) and O (2) are the same on both sides.
Learn more about balancing chemical equations at: https://brainly.com/question/8062886
Which statements best describe the functions of nucleic acids and proteins?.
The statement describing nucleic acid has been that nucleic acid provides the blueprint for the formation of proteins.
Nucleic acid has been the genomic material in the body that performs the function of storage of information. DNA and RNA are nucleic acids.
The proteins are the biomolecules that are composed of amino acid units bound by the polypeptide bond. The information for the correct sequence of binding of protein has resulted from the mRNA codes.
The correct sequence and folding results in the operational protein, that has been able to perform varying functions. The codes for the binding of protein have resulted from the blueprint consisting of nucleic acid.
Thus, nucleic acid performs the function of acting as a blueprint for the formation of proteins.
For more information about proteins, refer to the link:
https://brainly.com/question/2193769
What happens to the atoms in food once animals eat them?
they are destroyed
they are used to make the animal grow
they are released as waste
Answer:
i think
they are used to male the animal grow
Once the animal eats the food, the atoms in food are used to make the animal grow.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
Learn more about atom,here:
https://brainly.com/question/13654549
#SPJ2
Analyze the reaction of solid magnesium and water. Which pair of reactants and products in the table below represent the correct balanced equation for the reaction?
Answer:
3 is correct answer I think
Explanation:
Labor unions arose in the nineteenth century as increasing numbers of Americans took jobs in factories, mines, and mills in the growing industrial economy.
The Knights of Labor, founded in 1869, was the first major labor organization in the United States. The Knights organized unskilled and skilled workers, campaigned for an eight hour workday, and aspired to form a cooperative society in which laborers owned the industries in which they worked.
The Knights’ membership collapsed following the 1886 Haymarket Square riot in Chicago. By 1886 the American Federation of Labor (AFL), an alliance of skilled workers’ trade unions, was growing.
How do you break down an element?
Answer:
elements cannot be break downRound off your answer to one decimal place.
Answer: 10.4
Explanation:
ph is just as follows:
[tex]pH = -log[H_{3}O^{+}][/tex]
So plugging in our concentration we get:
[tex]-log(4.45*10^{-11})=10.35163999...[/tex]
Then rounding to one decimal place takes us to pH = 10.4
A force of 5N accelerates an object. The object mass is 50 g. What is the acceleration of an object?
Answer:
100 m/ s²
Explanation:
Newton's Second Law of Motion:
[tex] \boxed{ \mathsf{force = mass \times acceleration}}[/tex]
___________________
In the question:
Force applied = 5 N mass of the object experiencing force = 50 gNote that the quantities here must be in their SI units.
SI unit of Force is Newton(N).
SI unit of mass is kilogram(kg)
Force is already in it's SI unit, while mass isn't.
Converting mass from grams to kilograms:
1000 g = 1 kg
=> 1 g = 1/ 1000 kg
=> 50 g = 50/ 1000 kg
= 1/ 20 kg
___________________
Calculating acceleration:
[tex] \mathsf{5 = \frac{1}{20} \times acceleration }[/tex]
multiplying both sides by 20:
[tex] \implies \mathsf{5 \times 20= (\frac{1}{20} \times 20)\times acceleration }[/tex]
20 on the RHS gets canceled, for it's present on the numerator as well as the denominator.
[tex] \implies \mathsf{100= acceleration }[/tex]
So, here, we got acceleration = 100 m/s².
Since, the other quantities used in the formula are in their SI units, acceleration must be in it's SI unit as well.
The SI unit of acceleration is m/s²
___________________
Answer:
[tex] \boxed{ \mathsf{100 \:m/s^2= acceleration }}[/tex]
4. Initially, 1 mol of oxygen (assumed to be an ideal gas) has temperature 310 K and volume 12 L. We will allow it to expand to volume 19 L. (a) What would be the final temperature if the gas expands adiabatically
Answer:
490.83 oK
Explanation:
First of all, we better agree on the meaning of the word adiabatically. It means without the loss or gain of heat. So nothing is given up to or taken from the environment.
This also assumes that no change has occurred in the pressure.
T1 = 310 oK
T2 = ?
V1 = 12 L
V2 = 19 L
T1/V1 = T2/V2
310 / 12 = x/19 Multiply both sides by 19
310*19 / 12 = T2 Multiply 310 * 19 on the left.
5890 / 12 = T2 Divide by 12
490.83 = T2
NEED HELP ASAP PLZZZ
Answer:
Im pretty sure the answer is A. An electron moves from the FIFTH energy level down to the SECOND energy level.
Explanation:
What is a control group?
A group that changes the variable
The group that applies the variable
The group that tests the variable
A test group where the variable is not changed or applied Which of the following objects is transforming electrical energy into energy of motion?
Answer:
The group that tests the variable.
Explanation:
The group that tests the variable is a control group.
Answer:
C when testing the group put the varible in control
50 POINTS!!!! PLEASE HELP I AM BEGGING!!!!!!
3CH4 and C3H12 have the same number and kind of elements. How are they different?
PC13 ionic or covalent
Answer:
The bond between Phosphorus and Chlorine in PCl3 is covalent as chlorine needs one electron and phosphorus has metallic character and easily donate electron
which statement describes how vapor pressure occurs? (1 point)
a) Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert
pressure on the substance.
b) Some molecules of a substance have low enough kinetic energy to melt. These molecules exert pressure on the substance
c) Some molecules of a substance have low enough kinetic energy to vaporize. These molecules exert
pressure on the substance.
d) Some molecules of a substance have high enough kinetic energy to melt. These molecules exert pressure on the substance
Some molecules in a substance have a high kinetic energy hence they are able to convert into vapor. These molecules exert pressure on the liquid surface.
We know that the molecules that compose matter are in constant random motion. The kinetic energy of all the molecules in the liquid are not the same. The molecules at the surface of the liquid posses more kinetic energy than the molecules below.
Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert pressure on the substance.
Learn more: https://brainly.com/question/25273232
Answer:
Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert pressure on the substance.
Explanation:
Someone help me with this asap for 5p points and BRAINLIEST THANK YOU
Answer:
High trainability allows the owner to train the dog to handle certain things--some dog can be trained as police dogs and can be taught various jobs, so high trainability is very important
When a dog is Viscous, the dog will keep people away from your house, they will be able to keep danger away and because they are viscous they will be able to handle danger.
Loud bark- A loud bark from a dog can help alert other people when there is a intruder, it makes alot of noise so they can attract attention easily.
Quiet Bark- Ideal for pet owners who do not like noise, they bark quietly so they are not a bother to work or anyone doing something.
What is the atomic mass, in amu, of this atom?
Answer:
1) H - hydrogen - 1.100797
2) HE - helium - 4.00260
3) LI - lithum -6.941
Explanation:
On the periodic table the mass of carbon is reported as 12.01 amu. This is the average atomic mass of carbon. No single carbon atom has a mass of 12.01 amu, but in a handful of C atoms the average mass of the carbon atoms is 12.01 amu.
In order for a chemical reaction to take place, a certain amount of _____ must be present.
Answer:
The answer is energy. Please give me Brainliest!
Explanation:
Raising the concentrations of reactants makes the reaction happen at a faster rate. For a chemical reaction to occur, there must be a certain number of molecules with energies equal to or greater than the activation energy.
Please help.
Why does the temperature change when a powder is dissolved in water?
Answer:
In order for the powder to dissolve, each powder molecule must separate from the other powder molecules and be surrounded by water molecules. This shift in arrangement either absorbs or releases energy depending on the situation. It is due to the exchange of energy that the temperature of the solution fluctuates.
Explanation:
:)
I WILL GIVE BRAINLIEST TO THE RIGHT ANSWER
Which of the following substances would have the strongest
intermolecular forces of attraction present? *
A) HF (Hydrogen Fluoride)
B) HCI (Hydrogen Chloride)
C) HBr (Hydrogen Bromide)
D) HI (Hidrogen lodide)
Answer:
A) HF (Hydrofluoric acid)
Explanation:
dw I gotchu. So first off there are three types of intermolecular forces of attraction: 1) London-Dispersion, 2) Dipole-Dipole, 3) Hydrogen-Bonding Attraction Forces. That is also ranked in increasing strength, with Hydrogen-Bonding Attraction Forces being the strongest. Every molecule has London-Dispersion forces present and all the diatomic molecules listed have dipole moments of a certain debye (or Coloumb-meter) value. Both are irrelevant here so dw about that. Lets look at the strongest attraction: the hydrogen-bonding one. Now, don't get confused bc all of these acids are bonded to H bc hydrogen-bonding attraction forces only occur when H is bonded to N, O, or F. So Process of Elimination, hydrofluoric acid (HF) has the strongest intermolecular forces of attraction.
Note: If you don't know what inter/intra molecular forces of attraction are, ill give u a quick summary. Intermolecular refers to electrostatic attractions between molecules while intramolecular refers to the actual bonds, single, double, or triple, binding the atoms together. Well there you have it, have a great day. :)
Plzzzzz helpppppp meeeee I am dooo confused
Answer:
I think the person is not move
Explanation:
b/c the net force is zero............. 100 w + 100 E
............... 100+(-100 = 0