Answers
Answer:
The 3rd one
Explanation:
Related Questions
please help guys the question is
give reasons
a. we have to separate the mixture
b. All impure substances are not harmful.
c. A mixture of iron fillings and sand can be separated by using a magnet
d. A sentences "shake before well use" is written on the bottle of the medicine.
Answers
Answer:
(a )people separate mixtures in order to ger a specific substance that they need.
A certain polytomic ion contains 49 protons and 50 electrons. What's the net charge of this ion?
Answers
Answer:
the charge is -1
Explanation:
because the charge of proton is +and electron -
charge = +49 +(-50)
= -1
Answer:
Net charge is -1
Explanation:
[tex]{ \sf{net \: charge = p {}^{ + } + {e}^{ - } }} \\ = { \sf{49 + ( - 50)}} \\ = - 1[/tex]
How did Earth come to have an oxygen atmosphere?A.Precambrian rocks released oxygen into the atmosphere.B.Volcanoes released oxygen into the atmosphere.C.Early organisms created oxygen from other gases in the atmosphere.D.Oxygen was the primary gas originally in Earth's atmosphere.
Answers
Chlorine has an electronegativity value of 3.0. Given the electronegativity of N, O, and P (3.0, 3.5, and 2.1, respectively), which of the following molecules has nonpolar bonds?a. NCl3b. Cl2Oc. PCl3d. All of thesee. None of these
Answers
Answer:
a. NCl3
Explanation:
All the elements stated are non metals. Generally the bond between non metals is a covalent bond. However depending on how the electrons are shared, this bond can either be polar or non polar.
A non polar covalent bond is formed when the electrons are shared equally between the atoms.
A way to determine if a bond is non polar or polar covalent is by comparing the electronegativity values.
If the electronegativity difference is less than 0.5, it is regarded as a non polar covalent bond.
Going back to the question;
Between N and Cl; the electronegativity difference is 3.0 - 3.0 = 0
Between Cl and O; the electronegativity difference is 3.5 - 3.0 = 0.5
Between Cl and P; the electronegativity difference is 3.5 - 2.1 = 1.4
From these we can tell that the correct option is option A.
If a reaction is first-order with respect to a particular reactant, when the concentration of that reactant is increased by a factor of 2, the reaction rate will _____.
Answers
Answer:
It would increase by a factor of 2
Explanation:
The rate law for a fist order reaction is given as;
A --> B
rate = k [A]
upon doubling the concentration, we have;
rate = k [A]
rate 2 = k 2 [A]
Dividing both equations;
rate 2 / rate 1 = k 2 [A] / k [A]
rate 2 / rate 1 = 2 / 1
The ratio between rate 2 and rate 1 is 2 : 1. This means that the reaction rate would also increase by a factor of 2.
Which element will have a higher electronegativity?
A. Fluorine
B. Hydrogen
C. Bromine
D. Phosphorus
Answers
Answer:
fluorine is the most electronegative element,
Explanation:
while francium is one of the least electronegative. (Helium, neon, and argon are not listed in the Pauling electronegativity scale, although in the Allred-Rochow scale, helium has the highest electronegativity.)
Answer:
A. Fluorine
Explanation:
It said that according to periodic law that the group seven elements are highly electronegativity and in reduce down the group
Which mean that it is Fluorine
Solid cesium bromide has the same kind of crystal structure as CsCl which is pictured below: If the edge length of the unit cell is 428.7 pm, what is the density of CsBr in g/cm3.
Answers
Answer:
[tex]\mathbf {density \ d =4.4845 \ g/cm^3}[/tex]
Explanation:
Let recall the crystal structure of CsBr obtains a BCC structure. In a BCC structure, there exist only two atom per cell.
The density d of CsBr in g/cm³ can be calculated by using the formula:
[tex]\mathtt{ density \ d = \dfrac{z \times molar\ mass \ (M)}{ edge \ length \ (a) \ \times avogadro's \ number \ (N)}}[/tex]
where;
z = 1 mole of CsBr
edge length = 428.7 pm = (4.287 × 10⁻⁸)³ cm
molar mass of CsBr = 212.81 g/mol
avogadro's number = 6.023 × 10²³
[tex]\mathtt{ density \ d = \dfrac{1 \times 212.81}{(4.287 \times 10^{-8})^3 \times 6.023 \times 10^{23}}}[/tex]
[tex]\mathtt{ density \ d = \dfrac{ 212.81}{47.4540533}}[/tex]
[tex]\mathbf {density \ d =4.4845 \ g/cm^3}[/tex]
Nitric acid is a strong acid, sodium hydroxide is a strong base, and sodium nitrate is a soluble salt. Which of the following is the net ionic equation for the reaction?
HNO_3(aq) + NaOH(aq) ------------->NaNO_3(aq) + H_2O(l)
A) H^+(aq) + OH^-(aq) ---------------->H_2O(l)
B) NO_3^-(aq) + Na^+(aq)-----------> NaNO_3(s)
C) H^+(aq) + NaOH(aq) ------------>Na^+(aq) + H_2O(l)
D) HNO_3(aq) + OH^-(aq)---------> NO_3^-(aq) + H_2O(l)
E) none of the above
Answers
which of the following is an example of precipitate a. liquid evaporating into gas b. a solid form from a frozen liquid c. a chunky solid form from 2 liquids combining d. a liquid solution that contains 2 substances
Answers
Answer:
B and C
Explanation:
The google definition of precipitate is "a solid formed by a change in a solution, often due to a chemical reaction or change in temperature that decreases solubility of a solid". So in this case, the "solid formed from a frozen liquid" and "a chunky solid form from 2 liquids combining" are both examples of a precipitate.
The correct answer is C, a chunky solid form from 2 liquids combining.
In the laboratory, we usually mix two chemicals. When we mix the chemicals, we expect them to interact in one way or another. The interaction of those chemicals is known as a chemical reaction.
When we mix two liquid chemicals and they interact with each other to yield a solid product, we say that a chemical reaction has occurred and that such chemical reaction has produced a precipitate.
https://brainly.com/question/24276721
The reaction of butadiene gas (C4H6) with itself produces C8H12 gas as follows: The reaction is second order with a rate constant equal to 5.76 × 10−2 L/mol/min under certain conditions. If the initial concentration of butadiene is 0.200 M, what is the concentration in molarity remaining after 10.0 min? Report your answer to 3 decimal places.
Answers
Answer:
[tex]C_{C_4H_6}=0.179M[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]2C_4H_6\rightarrow C_8H_{12}[/tex]
And the rate law is:
[tex]\frac{dC_{C_4H_6}}{dt}=kC_{C_4H_6}^2[/tex]
Which integrated is:
[tex]\frac{1}{C_{C_4H_6}} =\frac{1}{C_{C_4H_6}^0}+kt[/tex]
In such a way, the concentration after 10.0 min is:
[tex]\frac{1}{C_{C_4H_6}} =\frac{1}{0.200M}}+5.76x10^{-2}\frac{L}{mol*min}*10.0min\\ \\\frac{1}{C_{C_4H_6}}=5.58\frac{L}{mol} \\\\C_{C_4H_6}=\frac{1}{5.58\frac{L}{mol} } \\\\C_{C_4H_6}=0.179M[/tex]
Regards.
When we react a weak acid with a strong base of equal amounts and concentration, the component of the reaction that will have the greatest effect on the pH of the solution is:______.
a. the acid.
b. the base.
c. the conjugate acid.
d. the conjugate base.
Answers
Answer:
d. the conjugate base.
Explanation:
The general reaction of a weak acid, HA, with a strong base YOH, is:
HA + YOH → A⁻ + H₂O + Y⁻
Where A⁻ is the conjugate base of the weak acid and Y⁻ usually is a strong electrolyte.
That means after he complete reaction you don't have weak acid nor strong base, just conjugate base that will be in equilibrium with water, thus (Strong electrolyte doesn't change pH:
A⁻ + H₂O ⇄ HA + OH⁻
As the equilibrium is producing OH⁻, the pH of the solution is being affected for the conjugate base
Right option:
d. the conjugate base.Using the following diagram, determine which of the statements below is true: The activation energy for the forward reaction is −60 J. The overall energy change for the forward reaction is −20 J. The activation energy for the reverse reaction is −80 J. The overall energy change for the reverse reaction is −40 J.
Answers
Answer:its saturated or unsaturaded
Explanation:
1. A
a stiff structure that surrounds and
protects a coll: found in plant, fungus, and some bacteria cells.
2.
is living things consisting of many cells.
3.
a green pigment that traps energy
from the sun.
the process in which plants and
some other organisms use the energy in sunlight to make food.
5. A
found in the nucleus of a cell,
a long nucleic acid molecule containing the genetic instructions
for the development and functioning of all living organisms.
Answers
Answer:
1 cell wall
2 yes
3 chloroplast
4 photosynthesis
5 Deoxyribonucleic acid (I believe)
hope this helped a little and pls mark brainiest if it did :)
Explanation:
The cell wall is a rigid layer that is found outside the cell membrane and surrounds the cell, providing structural support and protection.
The sugars can be classified as either aldoses or ketoses.
a. True
b. Fasle
Answers
Calculate the energy required to heat 1.30kg of water from 22.4°C to 34.2°C . Assume the specific heat capacity of water under these conditions is 4.18·J·g−1K−1 . Round your answer to 3 significant digits.
Answers
Answer:
The energy required to heat 1.30 kg of water from 22.4°C to 34.2°C is 64,121.2 J
Explanation:
Calorimetry is the measurement of the amount of heat that a body gives up or absorbs in the course of a physical or chemical process.
The sensible heat of a body is the amount of heat received or transferred by a body when undergoing a temperature variation (Δt) without there being a change in physical state. That is, when a system absorbs (or gives up) a certain amount of heat, it may happen that it experiences a change in its temperature, involving sensible heat. Then, the equation for calculating heat exchanges is:
Q = c * m * ΔT
Where Q is the heat or quantity of energy exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature (ΔT=Tfinal - Tinitial).
In this case:
[tex]c=4.18 \frac{J}{g*K}[/tex]m= 1.30 kg= 1,300 g (1 kg=1,000 g)ΔT= 34.2 °C - 22.4 °C= 11.8 °C= 11.8 °K Being a temperature difference, it is independent if they are degrees Celsius or degrees Kelvin. That is, the temperature difference is the same in degrees Celsius or degrees Kelvin.Replacing:
[tex]Q=4.18 \frac{J}{g*K}*1,300 g*11.8 K[/tex]
Q= 64,121.2 J
The energy required to heat 1.30 kg of water from 22.4°C to 34.2°C is 64,121.2 J
what is a chemical that is safe to use in food but in small amounts?
Answers
Answer:
Toxins
Explanation:
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Answers
Answer:
ELECTROLYTIC CELL
An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.
EXAMPLE
Nelsons cell and Downs cell
VOLTAIC CELL OR GALVANIC CELL
The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.
EXAMPLE
Daniel cell
Explanation:
Electrolytic cell by the non-spontaneous reactions covert the chemical energy into electical and volataic cells are those in which spontaneous redox reaction takes place.
What is cell?Cell is a device which converts chemical energy into electrical energy.
Electrolytic Cell: An electrolytic cell is an electrochemical cell in which a non-spontaneous redox chemical reaction occurs when an electric current is conducted through the solution.
Example- Electrolysis of sodium chloride, by which formation of sodium metal and chlorine gas takes place.
Voltaic cell: Voltaic cells are electrochemical cells in which a spontaneous redox chemical reaction occurs and creates electric current. These cells are also known by the name of Galvanic cells.
Example- It is used in the form of batteries which can be portable easily.
Hence, in electrolytic cells non - spontaneous reaction occur and in voltaic cell spontaneous reaction is occured.
To know more about cells, visit the below link:
https://brainly.com/question/1172236
#SPJ2
what is non metal?
help meh
Answers
The element which can not loose electron easily and having electronagtive character is called non-metal it has following property-1. it can not conduct heat and electricity1. it is netiher ductile not malleable3. it is not lsuturous and also not sonorous
Answer:
Non-metals are the elements which form negative ions by accepting or gaining electrons. Non-metals usually have 4, 5, 6 or 7 electrons in their outermost shell. Non-metals are those which lack all the metallic attributes. They are good insulators of heat and electricity. They are mostly gases and sometimes liquid.
A 30.5 g sample of a compound contains 9.29 g of nitrogen and the rest is oxygen. What is the empirical formula of the compound?
Answers
Answer:
The empirical formula of the compound is NO2.
Explanation:
The following data were obtained from the question:
Mass of compound = 30.5 g
Mass of nitrogen (N) = 9.29 g
Empirical formula of compound =?
Next, we shall determine the mass of oxygen in the compound. This can be obtained as follow:
Mass of compound = 30.5 g
Mass of nitrogen (N) = 9.29 g
Mass of oxygen (O) =?
Mass of O = mass of compound – mass of N.
Mass of O = 30.5 – 9.29
Mass of O = 21.21 g
Finally, we shall determine the empirical formula of the compound as follow:
Mass of nitrogen (N) = 9.29 g
Mass of oxygen (O) = 21.21 g
Divide by their molar mass.
N = 9.29 / 14 = 0.664
O = 21.21 / 16 = 1.326
Divide by the smallest
N = 0.664/ 0.664 = 1
O = 1.326/ 0.664 = 2
Therefore the empirical formula of the compound is NO2.
Find the pH of these buffer solutions using the information provided: 1L solution containing 80g of lactic acid (MW
Answers
Answer:
pH of the solution is 2.0
Explanation:
The lactic acid is a weak acid that is in equilibrium with water as follows:
Lactic acid + H2O ⇄ Lactate + H₃O⁺
And Ka for lactic acid: 1.38x10⁻⁴
Ka = 1.38x10⁻⁴ = [Lactate] [H₃O⁺] / [Lactic acid]
Initial concentration of lactic acid is (MW: 112.06g/mol):
80g * (1mol / 112.06g) / 1L = 0.714M
The equilibrium concentration of the species in the equilibrium are:
[Lactate] = X
[H₃O⁺] = X
[Lactic acid] = 0.714-X
Replacing in Ka expression:
1.38x10⁻⁴ = [X] [X] / [0.714-X]
9.8532x10⁻⁵ - 1.38x10⁻⁴X = X²
9.8532x10⁻⁵ - 1.38x10⁻⁴X - X² = 0
Solving for X:
X = -1.0x10⁻². False solution, there is no negative concentrations
X = 9.86x10⁻³M. Right solution.
As [H₃O⁺] = X
[H₃O⁺] = 9.86x10⁻³M
and pH = -log [H₃O⁺] = -log 9.86x10⁻³M
pH = 2.0
pH of the solution is 2.0A 1.2 L weather balloon on the ground has a temperature of 25°C and is at atmospheric pressure (1.0 atm). When it rises to an elevation where the pressure is 0.73 atm, then the new volume is 1.8 L. What is the temperature (in °C) of the air at this elevation?
Answers
Answer:
The temperature of the air at this given elevation will be 53.32425°C
Explanation:
We can calculate the final temperature through the combined gas law. Therefore we will need to know 1 ) The initial volume, 2 ) The initial temperature, 3 ) Initial Pressure, 4 ) Final Volume, 5 ) Final Pressure.
Initial Volume = 1.2 L ; Initial Temperature = 25°C = 298.15 K ; Initial pressure = 1.0 atm ; Final Volume = 1.8 L ; Final pressure = 0.73 atm
We have all the information we need. Now let us substitute into the following formula, and solve for the final temperature ( T[tex]_2[/tex] ),
P[tex]_1[/tex]V[tex]_1[/tex] / T[tex]_1[/tex] = P[tex]_2[/tex]V[tex]_2[/tex] / T[tex]_2[/tex],
T[tex]_2[/tex] = P[tex]_2[/tex]V[tex]_2[/tex]T[tex]_1[/tex] / P[tex]_1[/tex]V[tex]_1[/tex],
T[tex]_2[/tex] = 0.73 atm [tex]*[/tex] 1.8 L [tex]*[/tex] 298.15 K / 1 atm [tex]*[/tex] 1.2 L = ( 0.73 [tex]*[/tex] 1.8 [tex]*[/tex] 298.15 / 1 [tex]*[/tex] 1.2 ) K = 326.47425 K,
T[tex]_2[/tex] = 326.47425 K = 53.32425 C
explain how the liquid in a thermometer changes so that it can be used to measure a temprature
Answers
Answer:
The liquid that is often used in thermometers is chrome.
It is khwon for raising its volule when the temperature raises and vice-versa. ● the temperature and the volume are proprtional to each other so using Mathematics, scientists have figured out a way to benefit from it to make a thermometer.
Atoms that have a positive or negative electrical charge are called ________.
Answers
Explanation:
They are called or known as cations
Susan was investigating which glue would make the strongest craft stick tower. She
tested rubber cement, Elmer's glue-all, and Super Glue. She will test the strength of the
towers with books as the weight.
What is the independent variable?
Answers
Answer:
glue that would make the strongest craft stick tower.
Explanation:
Independent variable: In statistics and research methods, the term "independent variable" is determined as a variable that is being changed, controlled, or altered in an experiment or research by the researcher or the experimenter to see its effect on DV or dependent variable. However, it is said that independent variable directly effect the dependent variable.
Which of the following represents a compound made of five molecules? CO 5 C 2O 5 C 5O 5CO 2
Answers
Answer:
Co5
Please mark me brainliest so that I get encouraged to make more great answers like this one!
Answer:
GUYS ITS 5CO 2
Explanation:
1. Consider the following thermochemical reaction for kerosene:
2 C12H26(l) + 37 O2(g) 24 CO2(g) + 26 H2O(l) + 15,026 kJ
(a) When 21.3 g of CO2 are made, how much heat is released?
(b) If 500.00 kJ of heat are released by the reaction, how grams of C12H26 must have been consumed ?
(c) If this reaction were being used to generate heat, how many grams of C12H26 would have to be reacted to generate
enough heat to raise the temperature of 750g of liquid water from 10oC to 90oC?
2. Consider the reaction: NaNO3(s) + H2SO4(l) → NaHSO4(s) + HNO3(g) ΔH° = 21.2 kJ
How much heat must absorbed by the reaction system to convert 100g of NaNO3 into NaHSO4(s)?
3. What is the enthalpy change when 49.4 mL of 0.430 M sulfuric acid reacts with 23.3 mL of 0.309 M potassium
hydroxide?
3.
H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(l) ΔH° = –111.6 kJ/mol
Answers
do you have the specific heat for part 2?
At a certain temperature the equilibrium constant, Kc, equals 0.110 for the reaction: 2 ICl (g) ⇌ I2 (g) +Cl2 (g) What is the equilibrium concentration of ICl if 0.750 mol of I2 and 0.750 mol of Cl2 are initially mixed in a 1.00-L flask?
Answers
Answer:
The equilibrium concentration of ICl is 2.26 M
Explanation:
Chemical equilibrium is a state in which no changes are observed as time passes, despite the fact that the substances present continue to react. This is because chemical equilibrium is established when the forward and reverse reaction take place simultaneously at the same rate.
For the study of chemical equilibrium, the so-called equilibrium constant Kc is useful. Being:
aA + bB ⇔ cC + dD
the equilibrium constant Kc is:
[tex]Kc=\frac{[C]^{c} *[D]^{d} }{[A]^{a}*[B]^{b} }[/tex]
That is, the constant Kc is equal to the multiplication of the concentrations of the products raised to their stoichiometric coefficients by the multiplication of the concentrations of the reactants also raised to their stoichiometric coefficients.
For the reaction:
2 ICl (g) ⇌ I₂ (g) +Cl₂ (g)
the constant Kc is:
[tex]Kc=\frac{[I_{2} ]*[Cl_{2} ]}{[ICl]^{2} }[/tex]
Being Kc =0.110 and the concentration being the amount of moles of solute that appear dissolved in each liter of the mixture and being calculated by dividing the moles of the solute by the liters of the solution:
[tex][I_{2} ]=\frac{0.750 moles}{1 L} =0.750 \frac{moles}{L}[/tex][tex][Cl_{2} ]=\frac{0.750 moles}{1 L} =0.750 \frac{moles}{L}[/tex]and replacing in the constant we get:
[tex]0.110=\frac{0.750*0.750}{[ICl]^{2} }[/tex]
Solving, you get the ICl concentration at equilibrium:
[tex][ICl]^{2} =\frac{0.750*0.750}{0.110 }[/tex]
[tex][ICl] =\sqrt{\frac{0.750*0.750}{0.110 }}[/tex]
[ICl]= 2.26 M
The equilibrium concentration of ICl is 2.26 M
According to the following reaction, how many moles of ammonia will be formed upon the complete reaction of 31.2 grams of nitrogen gas with excess hydrogen gas ? nitrogen(g) + hydrogen(g) ammonia(g)
Answers
Answer:
4.46 mol of NH3
Explanation:
The equation of he reaction is given as;
2N + 3H2 --> 2NH3
From the stochiometry of the reaction, 1 mol of Nitrogen produces 2 mol of Ammonia.
Mass of Nitrogen = 31.2g
Molar mass of Nitrogen = 14g/mol
Number of moles = Mass / Molar mass = 31.2 / 14 = 2.23 mol
Since 1 mol of N = 2 mol of NH3;
2.23 mol of N2 would produce x
x = 2.23 * 2 = 4.46 mol of NH3
place the following substances in Order of decreasing boiling point H20 N2 CO
Answers
Answer:
-195.8º < -191.5º < 100º
Explanation:
Water, or H20, starts boiling at 100ºC.
Nitrogen, or N2, starts boiling at -195.8ºC.
Carbon monoxide, or C0, starts boiling at -191.5ºC.
When we place these in order from decreasing boiling point:
-195.8º goes first, then -191.5º, and 100º goes last.
Answer:
therefore, N2, CO, H20
Decreasing boiling point
Explanation:
the bond existing in H2O is hydrogen bond
bond existing in N2 is covalent bond, force existing is dipole-dipole-interaction
bond existing in CO is covalent bond , force existing between is induced -dipole- induced dipole-interaction
hydrogen bond is the strongest , followed by dipole-dipole-interaction and induced -dipole- induced dipole-interaction
the stronger the bond , the higher the boiling point
therefore, N2, CO, H20
-------------------------------------->
Decreasing boiling point
For the following reaction, 6.99 grams of oxygen gas are mixed with excess nitrogen gas . The reaction yields 10.5 grams of nitrogen monoxide . nitrogen ( g ) oxygen ( g ) nitrogen monoxide ( g ) What is the theoretical yield of nitrogen monoxide
Answers
Answer:
13.11 g.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below :
N2 + O2 —> 2NO
Next, we shall determine the mass of O2 that reacted and the mass of NO produced from the balanced equation. This is illustrated below:
Molar mass of O2 = 16x2 = 32 g/mol
Mass of O2 from the balanced equation = 1 x 32 = 32 g.
Molar mass of NO = 14 + 16 = 30 g/mol
Mass of NO from the balanced equation = 2 x 30 = 60 g.
From the balanced equation above,
32 g of O2 reacted to produce 60 g of NO.
Finally, we shall determine the theoretical yield of NO as follow:
From the balanced equation above,
32 g of O2 reacted to produce 60 g of NO.
Therefore, 6.99 g of O2 will react to produce = (6.99 x 60)/32 = 13.11 g of NO.
Therefore, the theoretical yield of nitrogen monoxide, NO is 13.11 g.