Describe weighted average
Answer:
Explained below
Explanation:
In simple average, we just add all the given data variables and divide it by the number of data given.
However, when it comes to weighted average, what we do is that we multiply each given variable by their weights and then divide the sum of that by the sum of the weights.
Thus, if the variables are denoted by x and their weights are denoted by y, then we have;
Weighted average = Σ(xy)/Σy
mention two factors which affect pressure due to liquid contained in a vessel
Answer:
depth of the liquid and nature of liquid affects the pressure due to liquid contained in a vessel
Answer:
Two factors influence the pressure of fluids. They are the depth of the fluid and its density. A fluid exerts more pressure at greater depths
When it’s summer in the northern hemisphere what Season is it in the Southern Hemisphere
Answer:
Winter
Explanation:
I dont know but whatev
Answer:
Winter
Explanation:
The seasonal cycle in the polar and temperate zones of one hemisphere is opposite to that of the other. Therefore, When it is summer in the Northern Hemisphere, it is winter in the Southern, and vice versa.
hope it helps :)
How many atoms of hydrogen are there in 36 g of NH4?
Answer:
hope it helps you
Explanation:
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I need help with question 5
Answer:
B a spring being stretched
Plants in forests take up carbon dioxide from the atmosphere during photosynthesis. They transform the carbon dioxide into plant material. When plants die, their organic matter is often worked into the soil by decomposers. Some of this organic matter remains within the soil and forest floor, and some of it is taken up by other living things.
Based on this information, what role do forests play in the carbon cycle?
A.
Forests are carbon sinks because they store carbon.
B.
Forests are carbon sinks because they do not absorb carbon dioxide when plants die.
C.
Forests are carbon sources because they emit carbon.
D.
Forests are carbon sources because they can be burned to emit carbon dioxide.
Answer: B. forests are carbon sinks because they store carbon
Explanation:forests take up carbon from the atmosphere through photosynthesis and from organic matter through decomposition. so, forests are carbon sinks because they store carbon
How many moles of KOH are there in 27.5 mL of 0.250 M KOH?
Question 2 options:
4.31 × 10−3 mol KOH
6.88 × 10−3 mol KOH
7.24 × 10−3 mol KOH
8.13 × 10−3 mol KOH
9.21 × 10−3 mol KOH
Answer:
6.88 × 10^-3mol
Explanation:
Molarity = number of moles (n) ÷ volume (V)
According to this question, there in 27.5 mL of 0.250 M KOH, the number of moles of KOH can, therefore, be calculated as follows:
number of moles = molarity × volume
Volume of KOH = 27.5mL = 27.5/1000
= 0.0275L
n = 0.0275 × 0.250
n = 0.006875 mol
n = 6.88 × 10^-3mol
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
Fl atomic number: 9
Fl atomic mass: 10
(ps i have two of these but can’t figure out the last)
Answer:
The number of electrons in the orbit is wrong they have to be 9 and not 10since flourine is in group 7 the number of electrons in the outer most shell has to be 7 and not 2the first shell has 8 instead of 2 electronsI hope this helps
QUICK CHECK
Use the periodic table to select which type of bond is present and which of the listed properties is most
likely for each substance.
Substance
Type of bond
Likely property
A А
B
A
Cuzm
Ba
lonic
DO
covalent
02
С
D
metallic
Answer:
Coppell zinc,ironic bond
Explanation:
lt will give away two zinc atoms
Answer:
I will go with Sodium chlorine NaCl
Which is another word for 10 meters in the metric system?
Answer:
Dekameter
Explanation:
Is this population more likely to grows slowly or quickly in the next 10 years
nobody can say it is uncertain but in my opinion it will grow quickly in the next 10 years
How are the vapor pressure and boiling point of alkynes affected as the chain length increases?
Answer:
Answer to the following question is as follows;
Explanation:
Alkynes' vapour pressure and normal boiling points are altered when chain length grows, since vapour pressure rises while boiling point falls.
Vapour pressure always include pressure entered by vapour with its condensed phase, pressure include molecules force of attraction include vapour
Which element has 2 valence electrons in the 2s sublevel?
Answer:
beryllium is the answer.
I hope this will help you
Is FeS iron (ll) sulfide or iron (lll) sulfide?
Answer:
the valence of S is -2. For FeS to be neutral the valence of Fe used must be +2
and since Iron (II) has its valency 2, FeS will be Iron (II) Sulfide.
True or false, The universal gas constant, R, is . 0821 when we use mm Hg as our unit for pressure
Answer:
False
Explanation:
R = gas constant = 0.0821 atm•L/mol•K
Hiii pls help me to write out the ionic equation
Answer:
STEP I
This is the balanced equation for the given reaction:-
[tex] 2KOH_{(aq)} + H_2SO_4{}_{(aq)} \rightarrow K_2SO_4{}_{(aq)} + 2H_2O_{(l)} [/tex]
STEP II
The compounds marked with (aq) are soluble ionic compounds. They must be
broken into their respective ions.
see, in the equation KOH, H2SO4, and K2SO4 are marked with (aq).
On breaking them into their respective ions :-
2KOH -> 2K+ + 2OH-H2SO4 -> 2H+ + (SO4)2-K2SO4 -> 2K+ + (SO4)2-STEP III
Rewriting these in the form of equation
[tex] \underline{\pmb{2K^+} }+ 2OH^- + 2H^+ + \pmb{\underline{{SO_4{}^{2-}}} \: \rightarrow \: \underline{\pmb{2K^+}}} + \underline{\pmb{SO_4{}^{2-}}} + 2H_2O [/tex]
STEP IV
Canceling spectator ions, the ions that appear the same on either side of the equation
(note: in the above step the ions in bold have gotten canceled.)
[tex] \boxed{ \mathfrak{ \red{ 2OH^-{}_{(aq)} + 2H^+{(aq.)} \rightarrow H_2O{}_{(l)}}}} [/tex]
This is the net ionic equation.
____________________________
[tex] \\ [/tex]
[tex]\mathfrak{\underline{\green{ Why\: KOH \:has\: been\: taken\: as\: aqueous ?}}} [/tex]
KOH has been taken as aqueous because the question informs us that we have a solution of KOH. by solution it means that KOH has been dissolved in water before use.[Alkali metal hydroxides are the only halides soluble in water ]
. The Ksp of barium sulfate is 1.1 × 10–10. What is the sulfate-ion concentration of a 1.0-L saturated solution of BaSO4 to which 0.025 mol of Ba(NO3)2 is added? 4.4 × 10–9M 1.0 × 10–5M 6.6 × 10–5M 2.8 × 10–12M
Answer:
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
Explanation:
From the question we are told that:
[tex]Ksp=1.1*10^{-10}[/tex]
Volume of [tex]SO_4^{2-}=1.O[/tex]
Moles of [tex]Ba(NO_3)^2 =0.025[/tex]
Generally the equation for Ksp is mathematically given by
[tex]Ksp=[Ba^{2+}][SO_4^{2-}][/tex]
[tex]1.1*10^{-10}=[0.025][SO_4^{2-}][/tex]
Therefore
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
HELP ME PLZ Which of the following describes the structure of a fish's swim bladder?
A. Expands and contracts to allow the fish to rise or sink in the water
B. Internal organ filled with liquid
c. Holds urine until it can be released into the environment
D. Internal organ filled with air sacs
What is the name of the molecule shown below?
A) ethanol
B) ethanal
C) ethanoic acid
D) ethylamine
The name of the molecule shown is Ethanol.
What is Ethanol?Ethanol is a alcoholic substance that is formed from fermentation of glucose in the presence of yeast or microorganisms.
It has a chemical group that have methyl group, hydroxyl group OH which is bonded to carbon atom.
Therefore, The name of the molecule shown is Ethanol.
Learn more about ethanol below.
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what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?
Here, we have been given that;
$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 gHence, we can note that,
No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$(n) = 32.05
[tex] \\ [/tex]
Thus,
Molarity = 32.05 mg/LHence, molarity of the given solution will be 32.05 mg/L.
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction
Answer:
B. The amount of produd obtained/amount possible * 100
Explanation:
In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:
Percentage yield = Actual yield/theoretical yield × 100
- The actual yield is the amount of products got from a chemical reaction
- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).
CORRECT ANSWER ONLY ND WILL GIVE BRAINLIEST✌
Calculate the mass of nitrogen dioxide gas that would occupy
the same volume as 10g of hydrogen gas at ē same pressure and temperature
(H= 1.0 N = 14.0 O= 16.0) GAS LAWS/MOLES
Answer:
150g
Explanation:
Assuming they are ideal gases at the same temperature and pressure, equal moles of gasses have equal volume. IN this case, if we have 10g of hydrogen gas, that is 5 moles of H2 gas. That means 5 moles og NO2 will occupy the same volume which is 5*(14.0 + 16.0*2) = 230 g
Which pair of substances would react the
fastest?
a. Copper sheet and concentrated
nitric acid.
b. Copper powder and dilute nitric acid
C. Copper powder and concentrated
nitric acid.
Answer:
C. It has the highest rate of reaction. Copper has the highest TSA/V and concentrated nitric acid has huggest num of solute
For a reaction: aA → Products, [A]o -4.3 M, and the first two half-lives are 56 and 28 minutes, respectively. Calculate k (without units). Show Work!
A. 7.7 x 10^-2
B. 4.2 x 10^-3
C. 3.8 x 10^-2
D. 8.3 x 10^-3
E. None of these
Answer:
C.[tex]3.8\times 10^{-2}[/tex]
Explanation:
We are given that
Initial concentration, [tex][A]_o=4.3 M[/tex]
First half life, [tex]t_{\frac{1}{2}}=56[/tex]minutes
Second half life, [tex]t'_{\frac{1}{2}}=28[/tex]minutes
We have to find K.
The given reaction is zero order reaction.
We know that for zero order reaction
[tex]t_{\frac{1}{2}}=\frac{[A]_o}{2k}[/tex]
Using the formula
[tex]56=\frac{4.3}{2k}[/tex]
[tex]k=\frac{4.3}{2\times 56}[/tex]
[tex]k=3.8\times 10^{-2}[/tex]
Hence, option C is correct.
Zero-order reactions are the reactions when a surface or a catalyst is required for the reaction to proceed and is saturated by the reactant chemicals. The result of the concentration versus the time plot will be a straight line in a zero-order reaction.
[tex]3.8 \times 10 ^{-2}[/tex] is the value of k.
How to calculate the value of k?Given,
Initial concentration [tex][A_{0}][/tex] = 4.3 MThe first half-life of the reactant [tex](t \dfrac{1}{2})[/tex] = 56 minutesThe second half-life of the reactant [tex](t \dfrac{1}{2})[/tex] = 28 minutesThe given reaction in the question is of zero-order and for that, we know that,
[tex]t \dfrac{1}{2} = \dfrac{[A_{0}] }{2\;\rm k}[/tex]
Substituting the values in the equation we get:
[tex]\begin{aligned}56 &= \dfrac{4.3 }{2\; \rm k}\\\\\rm k &= {4.3 }{2 \times 56}\\\\\rm k &= 3.8 \times 10^{ -2}\end{aligned}[/tex]
Therefore, option C is correct.
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Which is a mixture?
Sodium metal
chlonne gas
sodium metal and chlonne gas
sodium chlonde (salt) and water
Answer:
I believe it's salt and water
Explanation:
not sure
Answer:
Mixture is a electronic device used to peel the things such as onion ,tomato,ginger, garlic etc.
______ exhibits the highest
intermolecular forces of the states of matter.
A. Solid
B. Liquid
C. Gas
D. Vacuum

when carbon is heated in a limited supply of oxygen, a gas is obtained.
1 .what is the name of this gas
Answer:
carbon monoxide
I think its correct but I am not sure
Answer: when carbon is heated in air carbon dioxide is formed, so is incomplete combustion which results in carbon monoxide.
Explanation: but when carbon dioxide reacts with more oxygen carbon monoxide is formed i guess.
I AM A BIT SURE BUT HOPE THIS HELPSSSS!!!!
To begin the experiment, Xavier washed his hands and put on safety goggles. He then measured 120 milliliters of tap water, 2.5 milliliters of baking soda, and 2.5 milliliters of citric acid. The initial temperature of the water was 23.5°C.
Next Xavier added the baking soda and citric acid to the water. The mixture immediately began to bubble vigorously, which lasted for about 30 seconds. The new temperature of the mixture was 17.7°C.
Is a chemical reaction taking place during Xavier’s experiment? How do you know?
WILL GIVE BRAINLIEST!!!!!!!!!!!!!!!
Answer:
Yes a chemical reaction is taking place.
Explanation:
There is a change in temperature along with bubbling. All signs of a chemical reaction.
Sodium and chlorine combine to form table salt.
2Na(s) + Cl2(g) → 2NaCl(s)
Does this reaction obey the law of conservation of mass?
Answer:
yes it does
Explanation:
because the ratios on the reactants and products are equal
The reaction 2Na(s) + Cl₂(g) → 2NaCl(s) obeys the law of conservation of mass.
Yes, this reaction obeys the law of conservation of mass. The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it is only rearranged.
In the given reaction, we have 2 sodium atoms (Na) on the left side and 2 sodium atoms (Na) on the right side. Similarly, we have 2 chlorine molecules (Cl₂) on the left side and 2 chlorine atoms (Cl) on the right side. Therefore, the number of atoms of each element is balanced on both sides of the reaction.
Additionally, the total mass of the reactants (2Na + Cl₂) is equal to the total mass of the product (2NaCl). The coefficients in the balanced equation represent the stoichiometric ratios, ensuring that the mass is conserved.
Hence, the reaction 2Na(s) + Cl₂(g) → 2NaCl(s) obeys the law of conservation of mass.
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