Answer:
178.463 amu
Explanation:
Average atomic weight of Hafnium is calculated as follows;
[(0.0016 × 173.940) + (0.0526 × 175.941) + (0.186 × 176.943) + (0.2728 × 177.944) + (0.1362 × 178.946) + (0.3508 × 179.947)] =0.278 + 9.234 + 32.911 + 48.543 + 24.372 + 63.125 = 178.463 amu
Therefore, average atomic weight of Hafnium is 178.463 amu
How many significant figures? A) 1234500_______ B) 1230.0_____ C) 0.10220____ D) 34560000______ E) 0.0000302010_______ F) 0.02050______ G) 1.250 x 105_____
Answer:
A) 5 sig figs
B) 4 sig figs
C) 4 sig figs
D) 4 sig figs
E) 5 sig figs
F) 3 sig figs
G) 5 sig figs
Explanation:
work for G- 1.250 x 105= 131.25
Significant digits/ figures are indeed the number in a value, typically a measure the contributes to the stock's accuracy. It's very first non-zero digit is being used to begin counting significant digits.
Any digits else than zero are relevant. In this, the number of digits is used to express a measurable or calculated amount.
Given:
[tex]A)\ 1234500 \\\\ B)\ 1230.0\\\\ C)\ 0.10220\\\\ D)\ 34560000\\\\ E)\ 0.0000302010\\\\ F)\ 0.02050 \\\\ G) \ 1.250 \times 10^5 \ \ OR\ \ 1.250 \times 105[/tex]
To find:
Significant figures=?
Solution:
For A, there are 5 significant figure.For B, there are 5 significant figure with 1 decimals.For C, there are 5 significant figure with 5 decimals.For D, there are 4 significant figure.For E, there are 6 significant figure with 10 decimals.For F, there are 4 significant figure with 5 decimals.For G, there are 9 significant figure with 8 decimals OR it has 3 significant figure.Learn more:
brainly.com/question/14804345
A gas in a 6.2 mL cylinder has a pressure of 1.4 atmospheres. A piston is pushed in until the gas volume is 3.1 mL, while the temperature remains constant. What's the final pressure of the gas in the cylinder?
Answer:
2.8 atm.
Explanation:
From the question given above, we obtained the following data:
Initial volume (V1) = 6.2 mL
Initial pressure (P1) = 1.4 atm
Final volume (V2) = 3.1 mL
Final pressure (P2) =?
The final pressure of the gas cylinder can be obtained by using the Boyle's law equation as shown below:
P1V1 = P2V2
1.4 × 6.2 = P2 × 3.1
8.68 = P2 × 3.1
Divide both side by 3.1
P2 = 8.68/3.1
P2 = 2.8 atm
Therefore, the final pressure of the gas cylinder is 2.8 atm
Answer:
2.8 atm
Explanation:
Ammonium phosphate [(NH4)3(PO4)] is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid H3PO4 with liquid ammonia. Calculate the moles of ammonium phosphate produced by the reaction of 1.50mol of ammonia.
Answer:
The correct answer is 0.50 mol (NH₄)₃PO₄
Explanation:
The balanced chemical equation between liquid ammonia (NH₃) and H₃PO₄ is the following:
3 NH₃ + H₃PO₄ → (NH₄)₃PO₄
According to the equation, 3 mol of ammonia produce 1 mol of ammonium phosphate. Thus, the stoichiometric ratio is 1 mol (NH₄)₃PO₄/3 NH₃. To calculate the moles of (NH₄)₃PO₄, we multiply the ratio by 1.50 mol NH₃:
1.50 mol NH₃ x 1 mol (NH₄)₃PO₄/3 NH₃ = 0.50 mol (NH₄)₃PO₄
Which of the following is equivalent to 251 torr?
A. 0.330 atm.
B. 1900 atm.
C. 29.4 psi.
D. All of these choices.
Answer:
Option A. 0.330 atm.
Explanation:
To know the correct answer, we simply do the following:
1. Conversion of 251 torr to atm
760 torr = 1 atm
Therefore,
251 torr = 251 torr / 760 torr × 1 atm
251 torr = 0.330 atm
2. Conversion of 251 torr to psi
1 torr = 0.0193 psi
Therefore,
250 torr = 250 torr / 1 torr × 0.0193 psi
250 torr = 4.825 psi
From the above illustrations, 251 torr is equivalent to both 0.330 atm and 4.825 psi. Therefore, only option A is correct.
An object has a mass of 10 grams and a volume of 5 cm3. What is the density of the object
Answer:
.0002
Explanation:
d=m/v
=10g/5cm3
=2g/come
=.0002 kg/cm3
Which of the following is an example of a quantitative observation? a. The piece of metal is longer than the piece of wood. b. Solution 1 is much darker than solution 2. c. The liquid in beaker A is blue. d. The temperature of the liquid is 60°C. e. At least two of the above (A-D) are quantitative observations.
Answer: d. The temperature of the liquid is 60°C.
Explanation:
A quantitative observation is an observation of measure of variables sing in the study or experiment . Variables can be length, weight, temperature , volume etc which can be measured.
From all the given options only option d. is describing a measure ( 60°C).
Hence, an example of a quantitative observation: "The temperature of the liquid is 60°C."
So correct option is d.
Classify each reactant and product in this reaction as an acid or base according to the Brønsted theory.
HF + H2O = F + H30+
Answer Bank
HF
H30+
F-
H2O
Answer:
Reaction: [tex]\rm HF + H_2O \rightleftharpoons F^{-} + H_3O^{+}[/tex].
[tex]\rm HF[/tex]: Bronsted-Lowry Acid.[tex]\rm H_3O^{+}[/tex]: Bronsted-Lowry conjugate Acid of [tex]\rm F^{-}[/tex]: Bronsted-Lowry conjugate Base of [tex]\rm HF[/tex].[tex]\rm H_2O[/tex]: Bronsted-Lowry Base.Explanation:
In the Bronsted-Lowry acid-base theory, the acid in a reaction is the species that loses a proton, [tex]\rm H^{+}[/tex]. The resultant species would be the conjugate base of that acid.
On the other hand, the Bronsted-Lowry base in a reaction is the species that accepts a proton [tex]\rm H^{+}[/tex]. The resultant species would be the conjugate acid of that base.
Identify the conjugate acid-base pairs in this reaction. Note that the two species in each pair are related by the gain or loss of a single proton. Therefore, their formula should look similar to each other.
For this reaction, [tex]\rm HF[/tex] and [tex]\rm F^{-}[/tex], as well as [tex]\rm H_2O[/tex] and [tex]\rm H_3O^{+}[/tex] form two similar-looking reactant-product pairs:
The reactant [tex]\rm HF[/tex] loses one proton to form the product [tex]\rm F^{-}[/tex]. Therefore, [tex]\rm HF\![/tex] would be the Bronsted-Lowry acid, while [tex]\rm F^{-}\![/tex] would be its conjugate base.The reactant [tex]\rm H_2O[/tex] gains one proton to form the product [tex]\rm H_3O^{+}[/tex]. Therefore, [tex]\rm H_2O\![/tex] would be the Bronsted-Lowry base, while [tex]\rm H_3O^{+}\![/tex] would be the conjugate acid.Which of the following may happen to astronauts when they return to Earth from space? (1 point)
They may feel dizzy because the flow of blood to and from the heart to the brain is affected in space.
They may feel dizzy because the heart pumps more blood per beat on Earth than in space.
Their heart rate may slow down because there is more blood to circulate around the body.
Their heart rate may slow down because there is less blood to circulate around the body.
Answer:
i believe its They may feel dizzy because the heart pumps more blood per beat on Earth than in space.
Explanation:
Answer:
They may feel dizzy because the flow of blood to and from the heart to the brain is affected in space.
Explanation:
How much Ca(NO3)2 should be weighed out to have 0.650 mol?A) 66.4 g.B) 97.68.C) 107 g.D) 133 g.E) 165 g.
Answer:
C) 107 g
Explanation:
Step 1: Calculate the molar mass of Ca(NO₃)₂
We can calculate the molar mass of Ca(NO₃)₂ by adding the masses of its elements.
M = 1 × Ca + 2 × N + 2 × 3 × O
M = 1 × 40.08 g/mol + 2 × 14.01 g/mol + 6 × 16.00 g/mol
M = 164.10 g/mol
Step 2: Calculate the mass corresponding to 0.650 moles of Ca(NO₃)₂
We multiply the number of moles by the molar mass.
0.650 mol × 164.10 g/mol = 107 g
40 points
Examine the table and write down what should be in each row below.
Write your answers on different lines for each row and place a common in
between each answer in that same row.*
Name
Symbol
Atomic
number
Mass
Number
Number of
neutrons
Number of
Electrons
Charge
Lithium-5
su
3
SB
1601
ISN
7
25Na
187
Your answer
Answer:
I am so confused about this i am so sorry but i cant there is to much going on
Explanation:
Sun2
Sun3
Sun4
Sun5
Sun6
Sun7
Sun8
Sun9
Sun10
A mass of 2 kg of acetylene is in a 0.045 m3 rigid container at a pressure of 4.3 MPa. Use the generalized charts to estimate the temperature.
Answer:
361 K
Explanation:
From the tables:
[tex]P_r=4.3/6.14=0.7,T_c=308.3\ K, R=0.2193\ kJ/kgK\\\\Volume (V)=0.045m^3, mass(m)=2kg\\\\v=V/m=0.045/2=0.0225\ m^3/kg[/tex]
Given that:
[tex]v=\frac{ZRT}{P}[/tex]
From the charts, at [tex]P_r=0.7,Z_g=0.59,T_r=0.94[/tex]
[tex]v_g=\frac{0.59*0.3193*0.94*308.3}{4300}=0.0127\ m^3/kg\ which\ is\ small\\ \\At\ T_r=1,Z=0.7,v=\frac{0.7*0.3193*1*308.3}{4300}=0.016\ m^3/kg\\\\At\ T_r=1.2,Z=0.86,v=\frac{0.86*0.3193*1.2*308.3}{4300}=0.0236\ m^3/kg[/tex]
Interpolating, we get [tex]T_r=1.17[/tex], T = 361 K
If Nurse Antonio adds that 7 grams of NaCI to water to make 1 liter of solution, what is the molar concentration of the solution? Use dimensional analysis and show how you completed the unit conversion.
Given :
Nurse Antonio adds that 7 grams of NaCI to water to make 1 liter of solution.
To Find :
The molar concentration of the solution .
Solution :
Molecular mass of NaCl , [tex]m=58.44\ g/mol[/tex] .
Now , number of moles is given by :
[tex]n=\dfrac{\text{Given weight}}{\text{Molecular Mass}}\\\\n=\dfrac{7}{58.44}\ mole\\\\n=0.12\ moles[/tex]
Molarity is given by :
[tex]M=\dfrac{\text{Number of moles}}{\text{Volume ( in Liters)}}\\\\M=\dfrac{0.12}{1}\ M\\\\M=0.12\ M[/tex]
Hence , this is the required solution .
What is the atomic mass of element X if 10.69 g XCl3 contains 5.55 g X?
Answer:
Atomic mass of element X = 115 g/mol (Approx)
Explanation:
Given:
Amount of XCl3 = 10.69 gram
Amount of X = 5.55 gram
Find:
Atomic mass of element X
Computation:
Moles of Cl = [Mass of Cl / Molar mass of Cl )
Moles of Cl = [(10.69 - 5.55 ) / 35.5]
Moles of Cl = 0.14479 (Approx)
Moles of X = 0.14479 / 3
Moles of X = 0.04826
Atomic mass of element X = 5.55 / 0.04826
Atomic mass of element X = 115 g/mol (Approx)
What tool do you use to measure mass?
Answer: Balance
Explanation: Mass is the amount of matter contained in a body.
In the firs reaction of glycolysis, glucose is converted to _________. The phosphate comes from __________.
A __________ is an enzyme that transfers the terminal phosphate of _________ to a substrate. The product of this reaction is then ______________ to fructose-6-phosphate.
Fructose-6-phosphate is then phosphorylated by a second __________ reaction, giving ___________.
Answer:
EMP Pathway - Embden Meyerhof Parnas Pathway
Answer:
glucose 6-phosphate; ATP
kinase; ATP; isomerized
kinase; fructose 1,6-bisphosphate
Explanation:
All of the statements describe hydrogen bonds EXCEPT: a. Hydrogen bonds account for the anomalously high boiling point of water. b. In liquid water, the average water molecule forms hydrogen bonds with two to three other water molecules. c. Individual hydrogen bonds are much weaker than covalent bonds. d. Individual hydrogen bonds in liquid water exist for many seconds and sometimes for minutes. e. The strength of a hydrogen bond depends on the linearity of the atoms involved in the bond.
Answer:
The correct option is e
Explanation:
Hydrogen bond is an intermolecular interaction/bonding that are formed between an electronegative atom (such as nitrogen, oxygen and fluorine) and a hydrogen atom. They are weak intermolecular bonds compared to covalent bonds but account for the high boiling point of water because of the strong hydrogen bond presence between the water molecules. Water molecules form hydrogen bonds between each other; since an oxygen atom (in a water molecule) has two lone pairs on it's outermost shell, it forms an hydrogen bond with two hydrogen atoms of other water molecule. Due to the fluidity of liquid water molecules, hydrogen bonds keep getting broken (although recreated/formed almost immediately), hence, individual hydrogen bonds in liquid water does not exist for long.
In the explanation above, it was stated that the strength of the hydrogen bond in water is the reason for it's high boiling point. The atoms in a water molecule are bent NOT linear hence the strength of hydrogen bond does not depend on the linearity of the atoms involved in the bond.
Aluminum has a density of 2.70 g/cm3 . What would the volume be in in3 of a piece of aluminum that weighs 185.3 g?
Answer:
The volume in in³ is 4.19 in³
Explanation:
To determine the volume in in³ ( cubic inches),
First, we will find the volume in cm³
From the question,
The density of aluminum = 2.70 g/cm³
Mass of the aluminum = 185.3 g
From,
[tex]Density = \frac{Mass}{Volume}[/tex]
Then,
[tex]Volume = \frac{Mass}{Density}[/tex]
Hence,
The volume of the aluminum in cm³ is
[tex]Volume = \frac{185.3 g}{2.70g/cm^{3} }[/tex]
[tex]Volume = 68.63[/tex] cm³
This is the volume in cm³
Now, for the volume in in³
1 in = 2.54 cm
∴ 1 in³ = 16.3871 cm³
Now,
If 16.3871 cm³ = 1 in³
Then, 68.63 cm³ = [tex]x[/tex]
[tex]x =\frac{68.63 \times 1 }{16.3871}[/tex]
[tex]x =4.19[/tex] in³
Hence, the volume in in³ is 4.19 in³
Answer:
4.19 g/cm3
Explanation:
Describe one limitation of geothermal energy?
What is the [A-]/[HA] ratio when the weak acid is in a solution two pH units above its pKa?a. 5:1b. 10:1c. 100:1d. 1:10e. 1:2
Answer:
c. 100:1.
Explanation:
Hello,
In this case, considering the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[A^-]}{[HA]} )[/tex]
And the pH two units above the pKa:
[tex]pH=pKa+2[/tex]
We obtain the required ratio as follows:
[tex]pKa+2-pKa=log(\frac{[A^-]}{[HA]} )\\\\\frac{[A^-]}{[HA]} =10^2=100[/tex]
Which is also a c. 100:1 ratio containing 100 parts of base per 1 part of acid.
Regards.
According to Henderson - Hawelbach equation:
[tex]\to pH = pka + \log (\frac{A^{-}}{HA})...........(a)[/tex]
According to question pH two unit above pka:
[tex]\to pH = pka + 2[/tex]
Put value of PH is equation (a)
[tex]\to pKa+2=pKa+ \log (\frac{A^{-}}{HA})\\\\\to 2= \log (\frac{A^{-}}{HA})\\\\\to (\frac{A^{-}}{HA})= 10^2\\\\\to (\frac{A^{-}}{HA})= 100\\\\[/tex]
So, the ratio is [tex][100 : 1][/tex]
Therefore, 100: 1 Ratio containing 100 part of base per 1 part of acid.
Learn more:
brainly.com/question/3934133
At elevated temperatures, methylisonitrile (CH3NC) converts to acetonitrile (CH3CN): CH3NC(g) --> CH3CN(g) At the start of the experiment, there are 0.200 mol of reactant (CH3NC) and 0 mol of product (CH3CN) in the reaction vessel. After 25 min of reaction, 0.108 mol of reactant (CH3NC) remain. The average rate of decomposition of methyl isonitrile, CH3NC, in this 25 min period is __________ mol/min. A. 3.7 x 10-3 B. 0.092 C. 2.3 D. 4.3 x 10-3 E. 0.54
Answer:
A. 3.7 x 10⁻³
Explanation:
In the beginning of the reaction there are 0.200 moles of reactant. After 25 minutes, remain 0.108 moles. That means the moles that wer descomposed are:
0.200 moles - 0.108 moles = 0.092 moles of reactant were descomposed.
That descomposition occurs in 25 minutes. The average rate of descomposition in moles / minute are:
0.092 moles Methyl isonitrile / 25 minutes = 3.7x10⁻³ mol/min.
Right option is:
A. 3.7 x 10⁻³Which of the following is a neutralization reaction?A. Na2O(s) + H2O(a) rightarrow 2NaOH(s).B. 4Na(s) + O2(g) rightqrrow 2Na2O(s).C. NaOH(s) + HCl(aaq) rightarrow NaCl(s) + H2O(aq).D. 2Ca(s) + O2(g) rightarrow 2CaO(s).
Answer:
C. NaOH(s) + HCl(aaq) rightarrow NaCl(s) + H2O(aq)
Explanation:
A neutralization reaction may be defined as the reaction where an acid when it reacts with some base, the products formed are a salt and water.
Simply, we can write,
acid + base ---> salt + water
Here in option (C),
NaOH is sodium hydroxide is an base
HCl is hydrochloric acid
NaCl is sodium chloride and is the common salt
H20 is water
So, option C). NaOH(s) + HCl(aaq) -----> NaCl(s) + H2O(aq) is a neutralization reaction.
Imagine you are going to eat your lunch soon. How did that stuff you eat originally get transformed into food by the plants or animals in the first place?
Why do Christians call Jesus "the Christ”? Christ comes from the Greek word for Messiah. Christ comes from the Greek word for salvation. Christ comes from the Latin word for Nazareth. Christ comes from the Latin word for Resurrection.
Answer:
it is A
Explanation:
Its on edge
Christians call Jesus "the Christ” because of the meaning behind the word. The term “Christ” comes from the Greek word “Christos” which means “the anointed one” or “the messiah”.
What is the reason for giving this title to Jesus ?This title was given to Jesus because of the many prophecies in the Old Testament that foretold of a coming messiah who would save the people of Israel from their enemies and bring peace and justice to the world.
The term “Christ” is also associated with the Latin word “Nazareth”, which is the town where Jesus was born. This further reinforces the idea of Jesus as the messiah, as it was prophesied that the messiah would be born in Bethlehem, which is a town near Nazareth.
Finally, the term “Christ” is also associated with the Latin word “resurrection”. This is because Jesus was believed to have been resurrected from the dead, which was seen as proof of his divine power and the fulfillment of the prophecies about the messiah. This further emphasizes the idea of Jesus as the messiah and savior of the world.
In conclusion, Christians call Jesus “the Christ” because of the meaning behind the word and because of the many prophecies in the Old Testament that foretold of a coming messiah who would save the people of Israel from their enemies and bring peace and justice to the world. The term is also associated with the Latin words “Nazareth” and “resurrection”, which further emphasize the idea of Jesus as the messiah and savior of the world.
Learn more about Testament at:
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Which term, speed or velocity, gives you more information about an object's motion? Why?
Answer:
Velocity
Explanation:
Both speed and velocity give speed information but only velocity gives information about the direction. So Velocity is more information. :)
Why do scientists use the scientific method?
A. It helps them analyze their data.
B. It helps them come up with testable scientific question.
C. It helps them prove their hypotheses.
D. It helps them avoid mistakes and produce reliable information.
Answer: D; It helps them avoid mistakes and produce reliable information
Explanation:
It says correct on my APEX test
What is the percent by mass of glucose in a solution made by dissolving 163 g glucose in 755 g water? Do you need to know the formula of glucose to do that calculation?
Explain
Answer:
Explanation:
%mass of glucose =( mass of gucose /mass of solution )x100%
= 163 / (755+ 163 )
= 17.76 %
Which of the following features describe your graph? Check all that apply. appropriate title of graph showing the effect of changing temperature on the volume of a gas appropriate axes titles time on the x-axis as the independent variable temperature on the y-axis as the dependent variable data sets are all at equal intervals on each axis range on both axes cover data points in such a way that there is not too much extra space on the graph
Answer:
you'll be fine if you mark all or one, it's really up to you
Explanation:
did it on edgenuity
Using a ruler, you measure the length of a rectangle to be 12.75 cm and the width to be 3.64 cm. Calculate the area of this rectangle
Answer:
46.41 cm
Explanation:
Area is length times width. Multiply 12.75 by 3.64 to get your answer. Don't forget to label it as cm!
what animal is most like to harmed when a beaver builds a dam
Answer:
Small fish or insects.
Explanation:
Students conduct a lab in which they neutralize an acid. Which of the following
is the last thing students should do before leaving the lab area?
The missing group of choices is as follows:
A. disassemble the equipment.
B. wash their hands.
C. record their observations.
D. clean the lab tables.
Answer:
The correct answer is - B. washing their hands.
Explanation:
Neutralization of an acid involves the reaction of the acid with a strong or week base ( on the basis of acid strength) which leads to the production of salt and water in aqueous solution.
Washing hand acid could be more dangerous as the acid reacts violently with water, however, after the neutralization of acid, there should be normal safety measures which are before leaving the lab one should wash their hand as chemicals used might be toxic or cause harmful effect to an individual.
Thus, the correct answer is - B. washing their hands.
