Answer:
letter d
Explanation:
hope it's help you
What is good conductor of electricity???
Answer:
Metals , silver and copper which allows to pass the electricity through it is called good conductor of electricity .
hope it is helpful to you ☺️
Diamond is an allotrope of :
a. carbon b. sillica
c. phosphorus c. Nitrogen
Answer:
carbon
Explanation:
because it is an allotrope of carbon
Answer:
Carbon
Explanation:
its literaly carbon
How could the experiment be changed to allow for a result to be shown for the insoluble food
colouring?
Answer:
no lo se yo hablo en español no en ingles
Please can someone answer quickly this do tomorrow morning
Which of the five signs should not be used by themselves?
Precipitate
Temperature change
Color change
Odor
Bubbles
Temperature change
Pls corret my answer if its wrong ●~●#CarryOnLearningThe normal boiling point of ethanol is 78.4 oC. Its enthalpy of vaporization is 38.6 kJ/mol. Estimate the vapor pressure of ethanol at 26.3 oC.
Answer: The vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
Explanation:
Given: [tex]\Delta H_{vap}[/tex] = 38.6 kJ/mol
[tex]T_{1} = 26.3^{o}C = (26.3 + 273) K = 299.3 K[/tex]
[tex]T_{2} = 78.4^{o}C = (78.4 + 273) K = 351.4 K[/tex]
Formula used to calculate the vapor pressure of ethanol is as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\[/tex]
Substitute the values into above formula as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\ \\ln \frac{760 torr}{P_{1}} = \frac{38600 J}{8.314 J/mol K}[\frac{1}{299.3} - \frac{1}{351.4}]\\\frac{760}{P_{1}} = 3.18\\P_{1} = 238.3 torr[/tex]
Thus, we can conclude that the vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
2. Find the slope of the line that passes between the points (12,5) and (2,3).
Write your formula for Slope
m=y2 −y1/x2-x1
Explanation:
3-5/2-12=1/5
plant growth is chemical change or physical change
Answer:
its a chemical change.
hope it helps.
stay safe healthy and happy...Answer: it is a chemical change because it involves chemical process
Explanation:
Which has more mass, 2 kg of steel or 5 kg of feather.
Answer:
5 kg of feather
Explanation:
the molar mass of oxygen(O2) is 32g. what is the mass of 1.05*10^25 molecules of O2
Answer:
3.36×10²⁶ g
Explanation:
Molar mass ( O2) = 32g/mol
mole(O2) = 1.05×10²⁵mol
Mass(O2) = ?
mole(n)= mass(m)/Molar mass(M)
n×M = m
1.05×10²⁵ mol × 32g/mol = mass
mass= 3.36×10²⁶ g
What is the balance equation for
_ Ba + _ HNO3 —> _ H2 + _ Ba(NP3)2
_ H3PO4 + _ NaOH —> _ H2O + _ Na3PO4
1st one
2_2_2
2nd one
3_1_1_3
i looked it up
¿Qué características distinguen a los coloides de otras mezclas?
If 250 grams of water is to be heated from 24.0°C to 100.0°C to make a cup of tea, how much
heat must be added? The specific heat of water is 4.18 J/g∙C
Answer:
[tex]\boxed {\boxed {\sf 79,420 \ J}}[/tex]
Explanation:
We are given the mass, a change in temperature, and the specific heat of water. We should use the following formula to solve this problem.
[tex]q=mc\Delta T[/tex]
In this formula, m is the mass, c is the specific heat, and ΔT is the change in temperature.
We know there are 250 grams of water and the specific heat of water is 4.18 J/g · °C.
We are given two temperature, so have to find the change in temperature. This is the difference between the initial temperature and final temperature. The water is heated from 24 °C to 100 °C. Therefore, the initial is 24 and the final is 100.
[tex]\bullet \ \Delta T= T_{final} - T_{initial} \\\bullet \ \Delta T=100 \textdegree C - 24 \textdegree C\\\bullet \Delta T= 76 \textdegree C[/tex]
Now we know all three of the variables and we can substitute them into the formula.
[tex]\bullet \ m= 250 \ g\\ \bullet \ c=4.18 \ J/g \textdegree C \\ \bullet \ \Delta T= 76 \textdegree C[/tex]
[tex]q= (250 \ g)( 4.18 \ J/g * \textdegree C)( 76 \textdegree C)[/tex]
Multiply the first two numbers together. The units of grams will cancel.
[tex]q= (1045 \ J/\textdegree C)(76 \textdegree C)[/tex]
Multiply again. This time, the units of degrees Celsius cancel.
[tex]q= 79420 \ J[/tex]
79, 420 Joules of heat must be added.
Why is the average atomic mass used when calculating grams of a
substance?
A. The exact weights of the isotopes are not known.
B. The elements in the substance are mixtures of their isotopes.
ОО
C. The average atomic mass is known to more significant figures.
D. The number of isotopes in the sample is constantly changing.
Answer:
The average atomic mass includes all of the isotopes of that atom which exist in nature. Almost all elements have at least two isotopes which naturally occur. Recall that isotopes are atoms with the same atomic number (protons), but a different number of neutrons.
This is the chemical formula for calcium phosphate:
Ca3PO42.
Calculate the mass percent of oxygen in calcium phosphate. Round your answer to the nearest percentage
Answer:
This is the chemical formula for calcium phosphate:
[tex]Ca_3(PO_4)_2[/tex].
Calculate the mass percent of oxygen in calcium phosphate. Round your answer to the nearest percentage
Explanation:
The molar mass of calcium phosphate is: 310.18g/mol.
In one mole of calcium phosphate there are 8 moles of oxygen atoms.
The atomic mass of oxygen in calcium phosphate is: 128.0 g
Hence, the mass % of oxygen in the given compound is:
[tex]mass% of Oxygen =\frac{mass of oxygen}{mass of calcium phosphate}*100\\&=\frac{128.0g}{310.18g} *100\\&=41.3[/tex]
Hence,mass%of oxygen is 41.3.
The mass of a neutron is
What are the basic elements of selection of proffesion?describe any two
Answer:
overall I think one answer
HELP HELP HELP PLSSS
Answer:
the answer is c kept in blue and with light
How to work out the amount of carbon dioxide that is released when fully combusted with 4kg of ethanol?
Answer:
There is 7642 grams of CO2 released
Explanation:
Step 1: Data given
carbon dioxide = CO2
Molar mass of carbon dioxide = 44.01 g/mol
Mass of ethanol = 4 kg = 4000 grams
Molar mass of ethanol = 46.07 g/mol
Step 2: The reaction
Combustion of ethanol means there is oxygen (O2) added. The products are CO2 and H2O.
C2H5OH + 3O2 → 2CO2 + 3H2O
Step 3: Calculate number of moles of ethanol
Moles ethanol = mass ethanol / molar mass ethanol
Moles ethanol = 4000 grams / 46.07 g/mol
Moles ethanol = 86.82 moles
Step 4: Calculate number of moles CO2
For 1 mol ethanol we need 3 moles to produce 2 moles CO2 and 3 moles H2O
For 86.82 moles of ethanol we'll have 2*86.82 = 173.64 moles CO2
Step 5: Calculate mass of CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 173.64 moles * 44.01 g/mol
Mass CO2 = 7642 grams
There is 7642 grams of CO2 released
True or false, If an atom is charged negative, it contains more electrons than protons.
Answer:
True
Explanation:
An atom would carry more protons if positively charged, an equal amount of both protons and electrons if neutral, and more electrons if charged negative.
Hi, in some texts number of water molecules released during polymerization is 2n but in others 2n-1 , why?
Answer:
Explanation:
Because you only have one repeat unit, n=1. 2n-1 becomes 2(1)-1 which is equal to one, meaning one molecule of H2O is produced, as is shown by the top condensation polymerisation reaction.
If you had two repeat units, n=2 so 2n-1=3. Three H2O molecules are produced because you would need two molecules of each reactant so three condesation reactions would occur and three molecules of H2O would be released.
Which statement about biogeochemical cycles is true?
O A. Plants are a part of the nitrogen and carbon cycles, but not the
water cycle.
O B. Plants are a part of the nitrogen, carbon, and water cycles.
O c. Plants are a part of the water and carbon cycles, but not the
nitrogen cycle.
D. Plants are a part
carbon cycle.
the water and nitrogen cycles, but not the
Answer: The answer is D:
Answer:
The answer is Option D
alguien que me pase una pagina para mirar nopor
Answer:
no pues nadie te pasa la pagina
For a reaction, AH = 176 kJ/mol and A SO = 0.285 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
A. At no temperature
B. T< 50 K
C. T>617 K
D. T< 617 K
Answer:
C. T>617 K
Explanation:
We are given that
[tex]\Delta H=176KJ/mol[/tex]
[tex]\Delta S=0.285KJ/K\cdot mol[/tex]
We have to find the temperature at which the reaction is spontaneous.
When
[tex]\Delta H>0, \Delta S>0[/tex]
Therefore, the reaction is spontaneous at certain range of temperature.
Option A is not true.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
When [tex]\Delta G[/tex] is negative, then the reaction is spontaneous.
[tex]\Delta G=176-0.285T[/tex]
When T<50
Suppose T=49 K
[tex]\Delta G=176-49\times 0.285>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
Option B is wrong.
C.T>617K
Suppose T=618 K
[tex]\Delta G=176-0.285\times 618=-0.13<0[/tex]
Therefore, [tex]\Delta G is negative[/tex].Hence, the reaction is spontaneous.
So, option C is true.
D.T<617 K
Suppose T=616 K
[tex]\Delta G=176-0.285\times 616=0.44>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
So, option D is not true.
Which of these will form hydrogen bonds? a. CH2Br2 b. CH3OCH2CH3 c. H2NCH2COOH d. H2SO3 e. CH3CH2OH
Answer:
Which of these will form hydrogen bonds?
a. CH2Br2
b. CH3OCH2CH3
c. H2NCH2COOH
d. H2SO3
e. CH3CH2OH
Explanation:
A hydrogen bond is the weak electrostatic force of attraction that exists between a covalently bonded hydrogen atom and a highly electronegative atom like N,O, and F.
For example, water has a hydrogen bond between the hydrogen atoms of one molecule and the oxygen atom of another molecule.
Among the given molecules,
a. CH2Br2 does not have a hydrogen bond because it does not have N or O or F.
b. CH3OCH2CH3 does not have a hydrogen bond.
Due to the absence of -OH or -NH or H-F bonds.
c. H2NCH2COOH shows hydrogen bonding.
d. H2SO3 has hydrogen bonding.
Due to the presence of -OH bond.
e. CH3CH2OH has hydrogen bonding.
Due to the presence of -OH bond.
what is the formulas for Calcium Chloride,Aluminium Sulphate and Sodium hydroxide. *
Answer:
Explanation:
Why is there a star * behind the question.
CaCl2
Al2(SO4)3
NaOH
which of the following pairs are ionic compounds ( Al,Cl),(Na,O),(Al,F)
Answer:
This answer I think it is Al,F
equator runs east and west all the way around the world,halfway between the south poles called the ______________and north poles called________________.
now na po plss....
then follow me☝
Answer:
hanigin ng mga pule natin
What is the basic difference between exergonic and endergonic reactions? Group of answer choices Exergonic reactions release energy; endergonic reactions absorb it. Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds. Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds. In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true.
Answer: the basic difference is Exergonic reactions release energy and an endergonic reactions absorb energy .
HOPE THIS HELPS!!!
Suggest two ways Becky could make tea dissolve more quickly
NO FIlES OR REPORTED
Answer:
heat mixture/stir
Explanation:
these are factors of dissolving of solvent faster
1. How do metals and non-metals react with acids? Write and explain the chemical equation for the reaction of magnesium with sulphuric acid and aluminium with hydrochloric acid.
Answer:
1. How do metals and non-metals react with acids?
Ans : Non metals does not react with acids while metals react with acids and produce hydrogen gas that burns with a 'pop'sound.
2. Write and explain the chemical equation for the reaction of magnesium with sulphuric acid and aluminium with hydrochloric acid.
Magnesium + sulphuric acid = Hydrogen + salt
Mg(s) + H2SO4 (aq) MgSO 4(aq) +H2 (g)
Aluminium + Hydrochloric acid = Hydrogen + Aluminium chloride
2Al(s)+6HCl(aq)→2AlCl3(aq)+3H2(g)
Answer:
Metals react with acid but non metals donot react with acid because
when a substance, reacts with acids it provides electrons to the H+ ions produced by the acids. Non-metals are acceptors of electrons and hence, they cannot donate electrons.
Explanation: H2SO4 + Mg(OH)2 = H2O + MgSO4. 2Al+6HCl→2AlCl3+3H2 2 A l + 6 H C l → 2 A l C l 3 + 3 H 2
