Answer:
Explanation: current= watts divided by voltage= 75/120= 0.625 amperes.Jan 14, 2017
how to get the atomic mass of hydrogen
Answer:
the atomic mass is 1.00784 u
Explanation:
to calculate the atomic mass you add up the mass of protons and neutrons.
How much heat energy is required to raise the temperature of 15g of silver from 25°C to 55°C, assuming the specific heat of silver
is 0. 24 J/gºC?
30
108
15 J
115 J
Answer:
108 j
Explanation:
.24 j/g-C * 15 g * (55-25) =
The pH of a solution is 8.43. What is the hydronium ion H30* concentration?
Why was October 12,1999 a historic day ?
The United Nations Population Fund designates today in history as the approximate day on which the world population reached six billion.
:)
what the similarities are between solid, liquid and gas particles of water.
Why do some scientists have difficulty communicating about their research to nonscientists?
Answer:
Non-scientists aren't exposed to the information that scientists have in their field of study. Scientists also have their research based on facts, while non-scientists can be biased on their beliefs and chose to ignore data and logic.
help this is for my cousin lol
Answer:
For camouflage, to blend in with their surroundings.
Explanation:
The solid, golden brown fur coat of the lion acts as camouflage and helps it hide to catch its prey, in low-lying grasses of the African savanna.
Which tool is used to measure an object’s mass?
A. Graduated cylinder
B. Meter stick
C. Digital thermometer
D. Electronic balance
1. As you increase the temperature of a gas in a sealed, rigid con-
tainer, what happens to the density of the gas? Would the results
be the same if you did the same experiment in a container with
a movable piston at a constant external pressure? Explain.
Answer:
If one increases the temperature of a gas in a sealed, rigid container, the density of gas will not change.
The key to this answer lays in the ideal gas equation:
pV = nRT
Thus, one can write: n = (m)/(M)where m is the mass of the gas and M is the molar mass of a gas.
pV = (m)/(M) RT
Hence, if one decides to divide the entire equation with volume, V, one may write:
p = (m)/(VM) RT
ρ = (m)/(V), where ρ is density
p = (ρ)/(M) RT
If one increases the temperature, in order to keep balance, the pressure will be increased, also. Container is rigid, so that means the volume is constant.
However, this will not affect the density because there is no difference in volume (V = const.) or the amount of gas (n = const).
If one had a container with a piston, yet, constant pressure, the change of the temperature will impact the density.
Explanation:
Outline the laboratory procedure for preparing a specific volume of a dilute solution from a concentrated stock solution
The various steps of how to prepare a specific volume of a dilute solution from a concentrated stock solution is described below.
Preparation of a dilute solution from stock solutionA stock solution is the solution that contains the standard concentration of a chemical compound.
A diluted solution is the solution shoes concentration has been decrease through addition of a solvent like water.
To prepare a dilute solution from a stock solution the following is done:
the needed volume of the stock solution is calculated,the volume is added to a volumetric flask,water is then added into the volumetric flask till it reaches the calibration line.Learn more about stock solutions here:
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How many outer atoms and lone pairs are present in a molecule with a trigonal pyramidal shape?.
Answer:
3 outer atoms and 1 lone pair
A person’s
mass
will be the same on Jupiter and Earth. A person’s
height
will be greater on Jupiter than on Earth.
In general, explain the difference between dietary fiber carbohydrates and sugar carbohydrates?
Answer:
Made up of glucose but passes through the body without being digested
Explanation:
Fiber: Made up of glucose but passes through the body without being digested. Sugar Alcohols: Not made up of glucose, therefore, they don’t directly affect blood glucose levels and are only partially digested. Although fiber is a carbohydrate, your body doesn’t digest it the same way.
What is the name and formula for the most common natural ore for copper?.
Answer:
Clalcopyrite is the most important and major source of copper material. It is widely spread copper-iron sulfide minerals with chemical formula (CuFeS^2)
The most common natural ore of copper is chalcopyrite with the chemical formula CuFeS₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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Are things on fire or is fire on things?
Answer:
It will depend on the situation to call it either way
Explanation:
For a typical human height of 2 meter what is the horizon distance on earth (r=6378) (b mars R=3,340
For a typical human height of 2m, horizon distance on earth and mars is 5km & 3.7km respectively.
How do we calculate the distance?Horizontal distance will be calculated as:
D = √h² + 2hr, where
h = height of the human = 2m
r = radius
First we calculate distance on earth where radius of earth is 6378km or 6378000mD = √(2)² + 2(2)6378000
D = 2√6378001 = 5051m = 5km
Now we calculate distance on mars where radius of mars is 3340km or 3340000mD = √(2)² + 2(2)3340000
D = 2√3340001 = 3674m = 3.7km
Hence required horizon distance on earth and mars is 5km & 3.7km respectively.
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Hello people ~
What are the most key factors of solid-state reactions?
a) Size of the particles
b) Mechanical properties of solids
c) Thermodynamic and kinetic factors
d) Environmental factors
Answer:
A and C
Explanation:
Size of the particles
It's denoted to surface area which is key factor of solid state reaction,higher the size late the reaction occursThermodyanmic and kinetic factors
the reaction depends upon temprature and rest factors like light , humidity etc
Answer:
Option AOption CExplanation:
What are Solid State Reactions ?
The reactions that are performed in the absence of solvents either by melting/grinding the materials together at the beginning of the reaction or by adding heat to the reaction are known as solid-state reactions Solid-state reactions are preferred because they reduce the generation of chemical wastes and costFactors
They depend on thermodynamic and kinetic factors, as mentioned before, heat is addedSize of the particles is also important because the rate of the reaction depends on the sizeNatural factors such as pressure, temperature, presence of sunlight, etc.What is a neutralization reaction?
Answer:
A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions
Explanation:hope this helps<33
Balance the equation below:
NO2(g) + H2O(l) + O2(g) → 4HNO3(aq)
HELP PLEASE!
Explanation:
This is an oxidation-reduction (redox) reaction:
4 NIV - 4 e- → 4 NV (oxidation)
2 O0 + 4 e- → 2 O-II (reduction)
NO2 is a reducing agent, O2 is an oxidizing agent.
How much heat is required, in calories, to raise the temperature of 57. 8 g of silver from 17. 0degrees C to 43. 5 degrees C, if the specific heat of silver= 0. 057 cal/g degrees C
Calculate the volume (in cm3) that 4. 00 cm3 of gas at 30 oC will occupy at 130oC when the pressure is kept constant
The volume of the gas is 5.32 cm³.
To calculate the volume of the gas, we use Charles' law.
Charles' lawCharles' law states that at constant pressure, the volume of a fixed mass of gas is directly proportional to its absolute temperature. This can be expressed mathematically as
Formula:
V/T = V'/T'............. Equation 1Where:
V = Initial volume of the gasV' = Final volume of the gasT = Initial temperature of the gasT' = Final temperature of the gas.Make V' the subject of the equation.
V' = VT'/T......... Equation 2From the question,
Given:
V = 4 cm³T = 30 °C = 303 KT' = 130 °C = 403 KSubstitute these values into equation 2
V' = (4×403)/303V' = 5.32 cm³Hence, the volume of the gas is 5.32 cm³.
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Solid sodium reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. How many molecules of hydrogen gas are produced when 27.5g of sodium are added to water?
Answer:
.598 moles of H2
Explanation:
Find the balanced equation of the reaction
2Na + 2 H2 0 ====> 2 Na OH + H2
27.5 gm of Na is 27.5/ 22.989 =1.196 moles
from the equation, each mole of Na produces 1/2 mole of H2
1.196 moles * 1/2 = .598 moles of H2
The reaction given by
2Na+2H_2O—»2NaOH+H_2Moles of sodium:-
Given mass/Molar mass27.5/231.196molSo
2mol Na Produces 1 mol H_21 mol Na Produces 0.5mol H_21.196 mol Na Produces=0.5(1.196)=0.598mol H_2Can a pressure change shift the equilibrium position in every reversible reaction? Explain
No, a pressure cannot change shift the equilibrium position in every reversible reaction.
How the pressure affect the reversible reaction ?If the pressure increases, the position of equilibrium shift in the direction with the small amount of molecules. This decreases the effect of the change. When the reaction will shift towards the products that means the reaction favor forward.
Factors that affect equilibrium position in reversible reaction.PressureCatalystTemperatureConcentrationFrom the above conclusion we can say that a pressure cannot change the shift of equilibrium position in every reversible reaction.
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The effective temperature of a star is related to its..
solar system.
luminosity.
absolute magnitude.
color.
Answer:
color
Explanation:
The effective temperature is directly related to the color of the star: the higher the temperature, the bluer the light emitted by the star.
For a gaseous reaction, N2 + 3H2 gives 2NH3. If 20 ml of nitrogen completely reacts with hydrogen, then what is the volume of produced NH3?
N2(g) + 3H2(g) → 2NH3(g)
20ml of nitrogen
to find:the volume of produced NH3
solution:So, 1 volume of nitrogen gas reacts with 3 volumes of hydrogen gas to produce 2 volumes of ammonia gas.
For this gaseous reaction in which all the reactants and products are gases we could write a chemical equation:
1 volume N2(g) + 3 volumes H2(g) → 2 volumes NH3(g)
1 volume of N2 is 20 ml so 2 volume of NH3 will be 40 ml .
Then , 20 ml N2 will give 40 ml of NH3
= 40 ml
Suppose two gasses in a container have a total pressure of 1.20 atm. What is the pressure of gas B if the partial pressure of gas A is 0.68 atm
Answer:
The partial pressure of gas B is 0.52atm
Explanation:
Pt = Pa + Pb
Pb = Pt - Pa
Pb = 1.20 atm - 0.68 atm
Pb = 0.52 atm
Help please!
An Arrhenius acid increases the concentration of hydrogen ions when dissolved in solution.
True
False
Answer:
The answer is true
Explanation:
An Arrhenius acid is a substance that increases the concentration of hydrogen ions in solution when it is dissolved in water.
Answer:
false
Explanation:
Suppose all the NO2 molecules were synthesized into N2O4. Given the equation 2NO2 ⇄ N2O4, how many moles of N2O4 would be produced? 2. 34 moles of N2O4
The moles of N₂O₄ would be produced by given moles of NO₂ is 1 mole.
What is stoichiometry?Stoichiometry of any reaction gives idea about the amount of species present before and after the completion of reaction.
Given chemical reaction is:
2NO₂ ⇄ N₂O₄
From the stoichiometry of the reaction it is clear that, 2 moles of nitrogen dioxide will produces 1 mole of N₂O₄.
Hence the produced moles of N₂O₄ is 1 mole.
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what is diffusion ,??
Diffusion is the net movement of anything generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential.
A sample of crushed rock is found to have 4. 81 x 10^21 atoms of gold, how many moles of gold are present in this sample?
A. 7. 99 x 10^-3 moles
B. 1. 57 x 10^-1 moles
C. 1. 25 x 10^3 moles
D. 2. 47 x 10^5 moles
Answer:
A
Explanation:
Recall that a mole of any substance contains 6.02 × 10²³ amounts of that substance.
In other words, a mole of gold atoms contains 6.02 × 10²³ gold atoms.
Hence, by dimensional analysis, we have that:
[tex]\displaystyle 4.81\times 10^{21} \text{ Au} \cdot \frac{1\text{ mol Au}}{6.02\times 10^{23} \text{ Au}} = 7.99\times 10^{-3} \text{ mol Au}[/tex]
Therefore, there is about 7.99 × 10⁻³ moles of gold present in the sample.
In conclusion, the answer is A.