The purpose of having experimental groups is to have sufficient data to be reasonably sure the relationship between the independent and dependent variable is not due to chance.
Answer:
the purpose of an experimental group are:
to enable the experimental study of one variable at a timeto check a different resultWhat are the controlled, independent, and dependent variables in a basic density column experiment?
WILL MAKE BRAINLIEST
Answer:
The Independent Variable is what we change or control in the experiment. The Dependent Variable is what we are testing and will be measured in the experiment. The Control Variables are what we keep the same during the experiment to make sure it's a fair test. hope this helps =)
Explanation:
HELP ASAP!!!
WAVES ALWAYS ORIGINATE WITH SOME
a
person
b
object
C
disturbance
Answer:
Disturbance
Explanation:
I believe it is Disturbance because waves are normally caused by wind, and wind classifies as Disturbance.
The complete
conversion of 90.0
grams of hydrogen to
ammonia would require
how many moles of
nitrogen gas?
Answer:
15moles
Explanation:
The balanced equation of this reaction is as follows:
N2 + 3H2 → 2NH3
Molar mass of H2 = 2g/mol
mole = mass/molar mass
mole = 90/2
mole = 45moles.
Based on the above balanced equation, 1 mole of nitrogen gas (N2) reacts with 3 moles of hydrogen gas (H2)
Hence, 45moles of hydrogen gas will produce (45 × ⅓) = 15moles of nitrogen gas (N2).
Answer:
Its 14.9 for those who are doing the escape room :)
Explanation:
DESPERATE!!!!! What is the molar mass of an unknown gas that has a density of 2.29 g/L at a pressure of 0.75 atm and a temperature of 88. degrees Celsius?
Answer:
The molar mass of the gas is 90.4g/mol
Explanation:
To solve this question we have to use the equation:
d = PM / RT
Where d is density of the gas = 2.29g/L
P is pressure = 0.75atm
M is molar mass of the gas = ??
R is gas constant = 0.082atmL/molK
T is absolute temperature = 88°C + 273.15 = 361.15K
Solving for M:
dRT / P = M
2.29L*0.082atmL/molK*361.15K / 0.75atm = M
90.4g/mol = M
The molar mass of the gas is 90.4g/mol
Ralph's friend invited him to attend a hard rock concert. Ralph did not want to go because he assumed other people who attended would be aggressive and unruly. Ralph's attitude is BEST described as an example of
prejudice
ambiguity
nonconformity
discrimination
impression formation
Answer:
Prejudice
Explanation:
Answer: your answer would be prejudice.
Which are different structures of the eye? Select four options.
please help !!!!!!!!
pupil
cochlea
cornea
auricle
retina
lens
Answer:
Pupil, Cornea, Retina, and Lens
Explanation:
How many grams of Fe2O3 are formed when 51.3 grams of iron, Fe, react completely with oxygen, O2? 4 Fe + 3 O2 --> 2 Fe2O3
The Fe is our limiting reactant here. First, convert the mass of Fe given to moles of Fe by dividing mass by the molar mass:
(51.3 g Fe)/(55.845 g/mol) = 0.9186 mol Fe.
According to the balanced equation, 2 moles of Fe2O3 are produced for every 4 moles of Fe that are consumed. In other words, half as many moles of Fe2O3 will be produced as there are Fe that react:
(0.9186 mol Fe)(2 mol Fe2O3/4 mol Fe) = 0.4593 mol Fe2O3.
Finally, convert the moles of Fe2O3 back to grams by multiplying by the molar mass of Fe2O3:
(0.4593 mol Fe2O3)(159.6882 g/mol) = 73.3 g Fe2O3.
So, 73.3 grams of Fe2O3 are formed.
Una solución hallar punto de vista física y punto de vista químico (sal) 50g de sal y 250 ml de agua hallar %m/m %m/v molalidad, molaridad, fracción molar del soluto y del solvente
Answer:
% m/m = 16.6%
% m/v = 20%
3.42 m (molalidad)
3.42 M (molaridad)
Fraccion molar del soluto = 0.06
Fraccion molar del solvente = 0.94
Explanation:
Nuestra solución está compuesta por:
Soluto: 50 g de sal
Solvente: 250 mL de agua.
%m/m %m/v molalidad, molaridad, fracción molar del soluto y del solvente son distintas formas de definir la concentración:
% m/m son los gramos de soluto cada 100 g de solución.
No sabemos la masa de solución pero con la densidad del agua (solvente), sabemos que los 250 mL contienen 250 gramos de solvente. (Densidad del agua 1g/mL). En conclusión, la masa de solución es 50 g + 250g = 300
% m/m = (50g /300g ) . 100 = 16.6%
Vamos a definir que el volumen de la solución es igual al del solvente: 250 mL.
% m/v = la masa de soluto, cada 100 mL de solución
= (50 /250) . 100 = 20 %
Molalidad, son los moles de soluto por cada kg de solvente.
Convertimos gramos a kg → 250 g . 1kg /1000g = 0.25kg
Convertimos la masa de soluto (sal) a moles.
NaCl → 50 g . 1mol/ 58.45g = 0.855 moles
m = 0.855 /0.25 → 3.42 m (molalidad)
Molaridad son los moles de soluto por cada L de solución.
Convertimos mL a L → 250 mL . 1kg / 1000mL = 0.25 L
sabiendo que los moles de soluto son 0.855, en este caso la molaridad es igual a la molalidad ( 3.42 M)
Para calcular la fracción molar, necesitamos moles de soluto y de solvente.
Ya contamos con los moles de soluto.
Moles de solvente: 250 g . 1mol /18g = 13.89 mol
Moles totales = 0.855 + 13.89 = 14.745
Fracion molar del soluto: (0.855/ 14.745) = 0.06
Fraccion molar del solvente: (13.89 / 14.745) = 0.94
What is simple chemical test could you carry out to see if carbon dioxide has been produced
Carbon Dioxide
A positive test will result in the lime water turning milky. Lime water turns milky as the Calcium hydroxide (chemical name for limewater) reacts with carbon dioxide to form Calcium Carbonate which is insoluble in water and thus forms a milky white precipitate.
125 mL of a stock HCl solution was diluted to make 300 mL of a 0.750 mol/L HCl solution. What was the concentration of the original stock solution?
Answer: c= 1.8 mol/l
Explanation: amount of substance remains same.
Amount of substance n = c1·V1 = c2·V2 and c1= c2·V2/ V1
Original concentration c1= 300 ml·0.750 mol/l / 125 ml
How many grams of NaCl are in 3.5 mol of NaCl? Also, how many moles of NaCl are in 150 g of NaCl?
Answer:
204.5505 grams
2.5666 moles
Explanation:
For the first question, multiply 3.5 (# of moles) by 58.443 (g/mol for NaCl).
58.443 * 3.5
I'll distribute 3.5 into 58.443.
(3.5 * 50) + (3.5 * 8) + (3.5 * 0.4) + (3.5 * 0.04) + (3.5 * 0.003)
175 + 28 + 1.4 + 0.14 + 0.0105
203 + 1.4 + 0.14 + 0.0105
204.4 + 0.14 + 0.0105
204.54 + 0.0105
204.5505 grams
There are 204.5505 grams in 3.5 moles of NaCl.
For the second question, divide 150 (# of grams) by 58.443 (g/mol for NaCl). I'll convert both into fractions.
150/1 * 1000/58443
150000/58443
2.56660336 moles
2.5666 moles (rounded to 4 places to keep consistency with the first answer) are in 150 grams of NaCl.
11) How many grams are in 2.3 moles of magnesium chloride, MgCl,?
Answer:
218.98 grams
Explanation:
Given that,
No. of moles, n = 2.3
The molar mass of magnesium chloride is 95.211 g/mol.
We need to find the mass of 2.3 moles of magnesium chloride.
We know that,
No. of moles = given mass/molar mass
Let m be the given mass. So,
[tex]m=n\times M\\\\=2.3\times 95.211 \\\\=218.98\ g[/tex]
So, the required mass is equal to 218.98 grams.
In a metal crystal, describe the difference between “core electrons” and “valence electrons”
Answer:
Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels. This difference greatly influences the role of the two types of electrons in a chemical reaction.
HURRY ILL GIVE BRAINLIEST!
Match the cause to its effect.
Answer:
Cattles are giving nutrition supply throughout the year----some animals require nutrient enhancement for health
calves are given colostrum at birth----newborns require antibodies from their mothers
I dont want to write, so you know what the last option is
Explanation:
:) hope this helps
Nuclear equation problem
Please answer asap no explanation needed
(Look at picture)
Answer:
answer is will be C) ok alright
Is the formation of CO2(g) from its elements endothermic or exothermic?
Exothermic because the ΔH is negative.
Endothermic because the ΔH is negative.
Endothermic because the ΔH is positive.
Exothermic because the ΔH is positive.
Answer: Exothermic because the ΔH is negative.
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]
Exothermic reactions are those reactions in which heat is released and [tex]\Delta H[/tex] is negative.Endothermic reactions are those reactions in which heat is absorbed and [tex]\Delta H[/tex] is positive.
The reaction is exothermic as the heat is released during the formation of [tex]CO_2[/tex] as heat of formation of [tex]CO_2[/tex] is negative.
How many moles of H2O are in 359 grams of H2O
Answer:
359
i think
Explanation:
⚠️NO LINKS⚠️(it will get reported)
In a lab, students measured the mass of an unknown metal to be 46.4 g. The metal sample releases 769 J when it is cooled from 101.0°C to 30,00 °C, the
metal is most likely
Lead
. Copper
Mercury
Silver
Answer:
I'm thinking cooper but not sure
✓ What kind of carbon storages would be the most affected by humans?
Answer: Burning fuels?
Explanation: I’m not very sure actually
One use of CaCl2 is for salting roads in the winter. How much would the freezing point of water decrease if a 3.23 molal (m) solution of CaCl2 were applied? (Kf = 1.86°C/(mol/kg) for water and i = 3 for CaCl2.)
Answer:
Freezing point of water will decrease to -18.02°C
Explanation:
We start from the formula for freezing point depression, one of the colligative properties.
ΔT = Kf . m . i
ΔT = Freezing T° of pure solvent - Freezing T° of solution
m = molality
Kf = Cyoscopic constant (specific for each solvent)
i = numbers of ions dissolved (Van't Hoff factor)
CaCl₂ → Ca²⁺ + 2Cl⁻ i = 3
We replace each data:
0°C - T° F) = 1.86°C/m . 3.23 m . 3
T°F = - 18.02°C
whats another name for body cells (not sex cells) that are produced by mitosis?
Answer: Diploid Cells (?)
Explanation:
How many grams of BaCl2 can be made from 6 moles of Ba?
Answer:
823.98
Explanation:
Since there is only one Ba per atom you simply times 1 by 6 to get the number of mols of Ba per atom, then you times this by the atomic mass of Ba on the periodic table
Describe a method to investigate how the temperature changes when different masses of ammonium nitrate are dissolved in water
Answer:
Endothermic and Exothermic Reactions
Endothermic and Exothermic ReactionsIn this experiment you are investigating whether dissolving ammonium nitrate in water is an endothermic or exothermic reaction. An endothermic reaction absorbs energy from its surroundings (heat), so the reaction gets colder.
Explanation:
Don't forget to mark me as brainliest answer ☺
____________ is refining the extracted raw metals into a purest form
Answer:
Extractive metallurgy
Explanation:
Extractive metallurgy is the practice of removing valuable metals from an ore and refining the extracted raw metals into a purer form.
A sample of hydrogen gas has a volume of 145 mL when measured at 44
degrees C and 1.47 atm. What volume would the hydrogen sample occupy
at STP?
Answer:
[tex]186.01\ \text{mL}[/tex]
Explanation:
[tex]P_1[/tex] = Initial pressure = 1.47 atm
[tex]P_2[/tex] = Final pressure = [tex]10^5\ \text{Pa}[/tex]
[tex]T_1[/tex] = Initial temperature = [tex]44^{\circ}\text{C}[/tex]
[tex]T_2[/tex] = Final temperature = [tex]273.15\ \text{K}[/tex]
[tex]V_1[/tex] = Initial volume = 145 mL
[tex]V_2[/tex] = Final volume
We have the relation
[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow V_2=\dfrac{P_1V_1T_2}{T_1P_2}\\\Rightarrow V_2=\dfrac{1.47\times 101325\times 145\times 273.15}{(44+273.15)\times 10^5}\\\Rightarrow V_2=186.01\ \text{mL}[/tex]
Final volume of the sample is [tex]186.01\ \text{mL}[/tex].
The amount of heat energy needed to heat 200 g of water from 15 °C to its boiling point, and boil it, is
can you explain it further
Nevada's annual precipitation averages between 21 and 24 cm. In comparison,Washington state averages between 96 and 97 cm of precipitation per year. Which of these factors has the greatest impact on the difference in precipitation between these two states?
Answer:
Mountain ranges and prevailing winds.
Explanation:
Mountain ranges and prevailing winds are the factors that is responsible for the difference in the precipitation between Nevada and Washington states. The Washington state is located along the coastal region of pacific ocean and having more mountain ranges which causes more rainfall in that region while on the other hand, Nevada state comprise of plateau, basins and far away from the ocean which is the main cause of lower rainfall as compared to Washington state.
लेख्नुहोस् । (Deserts are very hot during the day and very cold
during the night. Give reason.)
Because deserts have such little water vapor in the air, it makes it harder to trap heat or cold in a desert. And at night, the sun no longer heats the desert and the heat from the day doesn't stay trapped. Because of this, some deserts can get extremely cold at night, dropping to temperatures below 40F.
Hope this helps!! Have a wonderful day!!
It is actually sand, which turns the entire phenomenon hot. Sand cannot hold the heat. It acts like a mirror to the sun. During the daytime, it stays warm, and when the Sun is absent it loses all its heat making the nights colder. There’s nothing in the desert that can either absorb heat from the sun or hold it on the surface when the sun is set.
Bacteria make their own food through photosynthesis making them autotrophs. * True or False
Answer: true
Explanation:
true
If 95 grams of Iron are needed to react with sulfur, how many grams of sulfur are involved in this reaction?
2 Fe + 3 S à Fe2S3
Answer:
You need a balanced equation.
2Fe(s) + 3S(s) ==> Fe2S3(s) ... balanced equation
Reactants are solid iron and solid sulfur
Product is iron(III) sulfide
A. 1.42 moles Fe x 3 moles S/2 moles Fe = 2.13 moles sulfur
B. 2.75 moles S x 2 moles Fe/3 moles S = 1.83 moles iron