Answer:
Average velocity of car = 50 km/h
Explanation:
Given information;
Distance cover by man in his car = 25 kilometer
Time taken by man to cover distance = 30 min
Find:
Average velocity of car
Computation:
Time taken by man to cover distance = 30 min
Time taken by man to cover distance = 30 / 60
Time taken by man to cover distance = 0.5 hour
Average velocity = Distance / Time
Average velocity of car = Distance cover by man in his car / Time taken by man to cover distance
Average velocity of car = 25 / 0.5
Average velocity of car = 50 km/h
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be
Options:
814 g
0.125 g
0.278 g
337 g
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
How to calculate mass?The mass of a substance can be calculated by multiplying the number of moles by its molar mass.
However, the number of moles of helium must be calculated as follows:
PV = nRT
Where;
P = pressureV = volumen = no of molesR = gas law constantT = temperature0.985 × 0.785 = n × 0.0821 × 301
0.773 = 24.7n
n = 0.773 ÷ 24.7 = 0.031moles
mass of He = 0.031 × 4 = 0.125g
Therefore, the number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
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Hydrogen and oxygen combine in
the ratio of 1:8 by mass to form
water. What mass of oxygen gas
would be required to react
completely with 3 g of hydrogen
gas?
Answer:
hhshshhxujejushwhbwhsjs s hs
A piece of wood displaces 12.5 mL of water and has a density of 0.97 g/ml. what is the mass of the piece of wood? what will happen if the wood is placed in water?
HELP PLEASE! ASAP YOUR DA BEST! 15 POINTS YALL
Density=0.97g/mL
Volume=12.5mL
[tex]\\ \sf \longmapsto Density=\dfrac{Mass}{Volume}[/tex]
[tex]\\ \rm\longmapsto Mass=Density(Volume)[/tex]
[tex]\\ \sf \longmapsto Mass=0.97(12.5)[/tex]
[tex]\\ \sf \longmapsto Mass=12.125g[/tex]
When 120 g of carbon reacts completely with 320 g of oxygen the mass of carbon dioxide formed will be?
two easy uses of mixture
Explanation:
it helps to make juices.
It helps to make concentrated acid into dilute acid.
Answer:
Explanation:
Here are a few more examples:
1. Smoke and fog (Smog)
2. Dirt and water (Mud)
Define force and speed
Force = The external energy that changes or tends to change the state of any body or object is called force.
Speed = The rate of distance is called speed.
Answer:
Force is a push or pull which changes or tend to change the position of a body.
The rate of change its position with time or magnitude is called speed.
El hipoclorito de sodio (NaClO), es vendido en una solución clara de ligero color verde-amarillento y un olor característico que se conoce con el nombre genérico Límpido, con una concentración del 6%. Pero para la desinfección de superficies el Límpido, debe ser diluido al 0,5%. Cuánto Límpido debemos sacar del recipiente para obtener 200 ml de una solución al 0,5%.
Respuesta:
16,7 mL
Explicación:
Paso 1: Información provista
Concentración inicial (C₁): 6%Volumen inicial (V₁): ?Concentración final (C₂): 0,5%Volumen final (V₂): 200 mLPaso 2: Calcular el volumen de la solución concentrada
Queremos preparar una solución diluida de hipoclorito de sodio a partir de una concentrada. Podemos calcular el volumen inicial que debemos tomar usando la regla de dilución.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂ / C₁
V₁ = 0,5% × 200 mL / 6% = 16,7 mL
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
please give me brainliest if you can :))
The gases in a hair spray can are at a temperature of 27oC and a pressure of 30 lbs/in2. If the
gases in the can reach a pressure of 90 lbs/in2, the can will explode. To what temperature must
the gases be raised in order for the can to explode? Assume constant volume. Show your work.
Using Gay Lussac's Law
[tex]\boxed{\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}}[/tex]
[tex]\\ \sf\longmapsto \dfrac{30}{27}=\dfrac{90}{T_1}[/tex]
[tex]\\ \sf\longmapsto T_1=\dfrac{90\times 27}{30}[/tex]
[tex]\\ \sf\longmapsto T_1=81°C[/tex]
Key Notes:-Gay Lussac's Law:-
It states that at constant volume (V),The pressure(P) of fixed amount of gas caries directly with its absolute temperature(T).
[tex]\\ \sf\longmapsto P\propto T[/tex]
[tex]\\ \sf\longmapsto \dfrac{P}{T}=Constant[/tex]
[tex]\\ \sf\longmapsto \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
[tex]\\ \sf\longmapsto P_1T_2=P_2T_1[/tex]
The final temperature of the gases with 90 lbs/in² is equal to 627°C assuming the volume is constant.
What is Gay Lussac's law?Gay-Lussac's law can be described as if the volume (V) of the gas remains constant then the pressure (P) is directly proportional to the absolute temperature (T) of the gas.
Gay Lussca's law in mathematical expression can be represented as:
P/T = k
It can be also represented as the pressure (P) being directly proportional to the temperature (T).
P ∝ T ( V of gas is constant)
or, P₁/T₁ = P₂/T₂
Given, the initial temperature of the gas, T₁ = 27°C = 27 + 273 = 300 K
The initial pressure of the gas, P₁ = 30 lbs/in²
The final pressure of the gas, P₂ = 90 lbs/in²
The final temperature of the gases in a hair spray can be determined as:
[tex]{\displaystyle \frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]
[tex]{\displaystyle T_2 =\frac{P_2\times T_1}{P_1}[/tex]
[tex]{\displaystyle T_2 =\frac{90\times 300}{30}[/tex]
T₂ = 900 K = 900 - 273
T₂ = 627°C
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A student was given a 2.850-g sample of a mixture of potassium nitrate and potassium bromide and was asked to find the percentage of each compound in the mixture. She dissolved the sample and added a solution that contained an excess of silver nitrate, AgNO3. The silver ion precipitated all of the bromide ion in the mixture as AgBr. It was filtered, dried, and weighed. Its mass was 1.740 g. What was the percentage of each compound in the mixture
Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
A piece of sodium metal can be described as?
describe how thin layer chromatography is used in the isolation and extraction of lipids
Thin layer chromatography(TLC) works with the principle of separation through adsorption.
It is used in the isolation and extraction of lipids through the following steps:
apply the lipid samples spots in the bottom of the plate.also apply sample solution to the marked spotpour the mobile phase into the TLC chamber and use a moist filter paper to cover it. this is done to maintain equal humidity.then place the plate in the TLC chamber and close it with a lid.the plate is immersed into the solvent (mobile phase) for its development. this is done, keeping in mind that the sample spot should be above the solvent.once the sample spots are developed, they are removed and dried.this is later viewed using the UV light chamber to see the isolation of the lipid sample.Learn more here:
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9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
What is the molecular formula?Write down the molecular formula of the given compounds.
i. Calcium Sulphate
ii. Sodium Carbonate
iii. Water
iv. Carbon Dioxide
v. Potassium Nitrate
vi. Ammonium Chloride
Answer:
A molecular formula consists of the chemical symbols for the constituent elements followed by numeric subscripts describing the number of atoms of each element present in the molecule.
The molecular formula of the given compounds are:
CaSO4Na₂CO₃H2OCO2KNO3NH4ClLiquids which do not wer the glass surface form a convex meniscus.True or false
Answer:
true is your answer
Explanation:
hope it helps
5+64
this is TOTALLY SOOOO hard so help me
^thats what she said
Answer:
69
Explanation:
I thought that I answer is correct
Answer:
The answer is 69
Explanation:
Because if you add one its 66, and so on, hope this helps! but if you add five it will be 69, if you need help with easy equations let me know
hii pls help me to balance the equation and state the symbols thanksss
Ca(s)+ H2O (l)----->H2 +Ca(oH)2
Ca(s)+2H2O(l)----->H2(g)+Ca(oH)2
I hope this helps
sorry if it's wrong
Temperature is measured in degrees C whereas heat is measured in
J
m
t
q
Answer:
J
Explanation:
Heat is measured in Joules (J)
What is cell wall? Where is it found?
Answer:
A cell wall is a fairly rigid layer surrounding a cell located outside of the plasma membrane that provides additional support and protection. They are found in bacteria, archaea, fungi, plants, and algae. Animals and most other protists have cell membranes without surrounding cell walls.
Explanation:
2. Calculate the density of a metal that occupies 17.75 cm and has a mass of 342.93 g. [D = m/V]
Answer:
19.32
Explanation:
the density is given by the mass over volume
the mass In this case is 342.93 and the volume is 17.75
d=342.93g/17.75cm
=19.32g/cm
i hope this helps
1a.calculate the relative formula mass of magnesium oxide when the relative atomic masses are O=16 Mg=24
1b.calculate the percentage by mass of magnesium in magnesium oxide
here's the answer to your question
The relative mass of the magnesium oxide (MgO) is equal to 40 g. The percentage by mass of magnesium in MgO is 60 %.
What is the mass percentage?The mass percentage of any element in a particular compound can be calculated from the number of parts by mass of the element in 100 parts by mass of a given compound.
Calculate the molar mass of the given compound by adding the atomic masses of the present elements. Then, the percentage of each element can be determined by dividing the total mass of the element by the molar mass of the compound multiplied by 100.
Given, the molecular formula of magnesium oxide is MgO. The atomic mass of Mg and O is 24 g and 16 g respectively.
The relative formula mass of the MgO = 40 g/mol
The mass percentage of the Mg = (24/40) × 100 = 60 %
Therefore, the mass percentage of the Mg in MgO is equal to 60 %.
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Calculate K for 2CO2(g) ⇔ 2CO(g) + O2(g)
given that the equilibrium concentrations of carbon monoxide, oxygen and carbon dioxide are 2.0 x 10-6 M, 1.0 x 10-6 M, and 0.25 M respectively.
Explanation:
here's the answer to your question
If the temperature of a reversible reaction in dynamic equilibrium decreases, how will the equilibrium change?
A. It will shift towards the endothermic reaction.
B. It will not change.
C. It will shift towards the products.
D. It will shift towards the exothermic reaction.
Answer:
D. It will shift towards the exothermic reaction.
Explanation:
A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result?
A.
Products will form with less energy input.
B.
No products will be formed.
C.
The products will form too quickly.
D.
Products will convert to reactants.
Answer:
B.
No products will be formed.
6.25 g of HCl(g), a strong acid, is dissolved in water to make a 280-ml solution.
Calculate the pH of the resulting solution.
pH= -log[0,611]= 0,21
that B) My color is sickle: I have a drop of water in my body when I was given heat, white powder was formed So who am i Lets identify. Write my chemical molecular formula
Explanation:
i don't understood your question ⁉️
and what do u mean by my color is sickle
what is meant by the term "boiling point of water"
Answer:
boiling point, temperature at which the pressure exerted by the surroundings upon a liquid is equaled by the pressure exerted by the vapour of the liquid; under this condition, addition of heat results in the transformation of the liquid into its vapour without raising the temperature
in case of water boiling point bring 0 degree
Answer:
it is the temperature at which water starts to boil. the temperate is 100°C or 212°F
PLEASE HELP ASAP
Barney was a very inventive scientist and tried to perform the same experiments as those by famous scientists from long ago. One of the most challenging experiments was to roll out a very thin film of gold and put X-ray film in a circle around it. The difficult part was to get ahold of some radioactivity that he could shoot at the thin film for gold. One day, he ran into The Great Gazoo and told him his goal. The Great Gazoo said he had the perfect substance for him that was radioactive and should work. The element was named after him and had the symbol Gz. Barney quickly went back to his lab to run the experiment. What Barney noticed is that all the radioactive particles went through the gold film and none of them ricocheted back, but all went straight through the gold. Being puzzled, he quickly went to the lab to analyze this unknown radioactive substance. He found that the atomic number was 119, the mass number was 305. After a few more tests, Barney realized what was wrong with Gz. Your task is to figure out what was wrong with Gz by answering the following questions:
Whose experiment was Barney trying to imitate?
Where would Gz be located on Earth’s periodic table, column and row?
Give as many details on Gz that you could predict based on its location on the periodic table: type of chemical (metal, metalloid, or nonmetal), reactivity, ionization energy, electronegativity, and size of element.
What would the elements electron configuration end in?
Why did all the radioactive particles go straight through the gold film?
What would the daughter product be for Gz? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, like Barney intended, what type of decay should Gz have had?
If Gz had worked correctly, what would the daughter product be? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, what element would it become?
Answer:
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
Explanation:
n this exercise they indicate that the particle Gz has atomic number 119 and atomic mass 305 amu, when reviewing the element periodicity table with this atomic number it has not yet been discovered, it should be in row 8 column 1 therefore it should be an alkali metal .
Therefore, it has only one electron in its last orbit.
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
16. The valency of sodium is +1 and that of chlorine is -1, why?
Answer:
It because ,sodium is a metal and chlorine is a non metal
1. Mg + HCl … + ….
2. NaOH + HNO3 … + ….
3. KOH + CuCl2 … + ….
4. Na2SO4 + BaCl2 … + ….
5. HCl + FeO à … + …
Explanation:
The answer is mentioned above.
Hope it helps.
