Answer:
1) 0.4045nm
2) 0.0027096117g/cm³
Explanation:
1) Using the value of ionic radius of aluminum ion r=0.143 nm, the length of each edge of the unit cell can be calculated as what nm?
In the question above, using a face centered cubic structure, we have:
For a face centered site of the cube,
The diagonal = 4r
Where r =Atomic or ionic radius of Aluminum
Let the edge length of the cube be represented by X
Therefore, we have based on Pythagoras theorem,
X² + X² = (4r)²
2X² = 16r²
Divide both sides by 2
X² = 8r²
Find the square root of both sides
X = √8 × r
Since r = 0.143nm
The length of each edge of the unit cell can be calculated as
X = √8 × 0.143nm
X = 0.4044650788nm
Approximately = 0.4045nm
2) Using atomic weight value of aluminum 27.0, the density of aluminum can be calculated as what g/cm^3
Density of an object = Mass of the Object / Volume of the Object.
The object in this question = Cube
Step 1
Volume of a cube = (Length of the cube)³
In the question above, side length of the cube = 0.4045nm
When would convert 0.4045nm to centimeters
= 1 nm = 1 × 10^-7 cm
0.4045nm =
Cross multiply
= 4.045 × 10^-7 cm
Volume of the Aluminum cube =(4.045 × 10^-7cm)³
= 6.618439112 ×10^-20cm³
Step 2
The atomic weight value of aluminum is given as 27.0 in the question
A face centered cubic structure has 4 atoms per unit cell.
1 Atomic mass or weight value = 1.6605 × 10^-24 grams
Hence, the mass of Aluminum is calculated as:
(4 atoms /1 cell )× 1 unit × (27/ 1 atom of Aluminium) × (1.6605 × 10^-24g/ 1 Atomic mass value)
= 1.79334 ×10^-22g
Density = Mass/Volume
= 1.79334 ×10^ -22g /6.618439112 ×10^-20cm³
= 0.0027096117g/cm³
Alex is on a special diet and needs to watch her intake of carbohydrates. Her doctor told her to maintain a 1,500 calorie per day diet and to make sure that these come from no more than 20% carbohydrates. She is snacking on pretzels and the nutrition label on the package says that there are 23 grams of carbohydrates per serving, which is 8% of the recommended daily allowance.
How many calories should Alex get from carbohydrates and what percentage of her total recommended intake of carbohydrates in grams is this snack? (1 gram of carbohydrate provides 4 Calories.)
Alex should get 300 Calories from carbohydrates, which is about 75 grams. This snack is 30% of her total grams of carbohydrates per day.
Alex should get 300 Calories from carbohydrates, which is about 33 grams. This snack is almost 70% of her total grams of carbohydrates per day.
Alex should get 300 Calories from carbohydrates, which is about 60 grams. This snack is about 38% of her total grams of carbohydrates per day.
Alex should get 300 Calories from carbohydrates, which is about 75 grams. This snack is 8% of her total grams of carbohydrates per day.
Answer: Alex should get 300 Calories from carbohydrates, which is about 33 grams. This snack is almost 70% of her total grams of carbohydrates per day.
Answer:
B
Explanation:
I think
the solution of ash of magnisium ribbon is ____
Answer:
Alkaline
Explanation:
The solution of ash of magnesium ribbon is alkaline.
Write the balanced equation for the production of oxygen gas and potassium chloride from the decomposition of potassium chlorate.
Answer:
2KClO₃→3O₂ + 2KCl
Explanation:
When Potassium Chlorate decomposes , the resulting products are oxygen gas and Potassium chloride . As per the equation above
C5H12, pentane, is a liquid at room temperature.
Can we predict from this information whether C4H10, butane, will be a liquid at room temperature?
A)Yes, it will be a liquid since pentane is a liquid.
B)Yes, it will be a liquid since it contains 4 carbon atoms.
C)We cannot be sure unless we find out its boiling point.
D)We cannot be sure unless we get the boiling point of propane, C3H8.
Answer:
C)We cannot be sure unless we find out its boiling point.
Explanation:
It is necessary to clearly explain here that simply observing two compounds of the same homologous series irrespective of how close they may be in the series will not give us the faintest idea regarding which one will be a liquid, solid or gas at room temperature.
However, to determine whether an unknown substance will be a liquid at room temperature, then its important to measure its boiling point. If the boiling point is above room temperature, and the melting point is below room temperature, the compound is a liquid. If the boiling point of the unknown substance is below room temperature, it is a gas.
It is now safe to conclude that cannot decide on the state of matter in which a compound exists unless we know something about its boiling point, not merely looking closely at the properties of its neighbouring compounds in the same homologous series
which statement describe a species adapting to changes in it’s environment?
Answer:
c
Explanation:
I would think adapting to changes would be the light moth being in a light trunk of a trees.
Answer:
a
Explanation:
dark colored moths become common after tree trunks become dark took the test.
What is the name of CH3CH2CH2COOH?
Answer:
Butanoic acid
Explanation:
what is the symbol for sodium chloride?
A second - order reaction has a rate constant of 0.06 M min - 1 . It takes min for the reactant concentration to decrease from 0.13 M to 0.088 M. Select one : O a . 73.4 O b . 7.80 O c . 6.50 O d . 61.2
Answer:
Choice D. Approximately [tex]61.2[/tex] minutes.
Explanation:
The reaction rate of a second-order reaction is proportional to the square of one of its reactants.
Let [tex]y[/tex] denote the concentration of that reactant (in [tex]\rm M[/tex].)Let [tex]t[/tex] denote time (in minutes.)Let [tex]k[/tex] denote the rate constant of this reaction. Assume that [tex]y_0[/tex] is the concentration of that reactant at the beginning of this reaction (when [tex]t = 0[/tex].) Because this reaction is of second order, it can be shown that:
[tex]\displaystyle y = \frac{1}{k\, t + (1/y_0)}[/tex].
The question states that the rate constant here is [tex]0.06\; \rm M\cdot min^{-1}[/tex]. Hence, [tex]k = 0.06[/tex]. For simplicity, assume that [tex]t = 0[/tex] when the concentration is [tex]0.13\; \rm M[/tex]. Therefore, [tex]y_0 = 0.13[/tex]. The equation for concentration [tex]y[/tex] at time [tex]t[/tex] would become:
[tex]\displaystyle y = \frac{1}{\underbrace{0.06}_{k}\, t + (1/\underbrace{0.13}_{y_0})}[/tex].
The goal is to find the time at which the concentration is [tex]0.088[/tex]. That's the same as solving this equation for [tex]t[/tex], given that [tex]y = 0.088[/tex]:
[tex]\displaystyle \frac{1}{0.06\; t + (1/0.13)} = 0.088[/tex].
[tex]t \approx 61.2[/tex].
In other words, it would take approximately [tex]61.2[/tex] minutes before the concentration of this second-order reactant becomes [tex]0.088\; \rm M[/tex].
Purple Group Header Warm-Up Why can I smell a chocolate bar even though it is a solid? Read the description of the office mystery and write your prediction below. On a warm afternoon, a Universal Space Agency office worker returned from lunch break and noticed the office smelled like chocolate. She didn't see anything in the air, but she noticed her coworker was opening the wrapper of a solid bar of chocolate. Why can the office worker smell the chocolate bar even though it is in solid form?
Answer:
The smell of a chocolate is from the presence of volatile compounds present in the chocolate bar which at room temperature readily changes phase from solid to liquid to vapor or gas
Explanation:
There are nearly 600 identified compounds present in a chocolate bar and out of these, there are volatile components which gives the chocolate bar its distinctive aroma.
These volatile chocolate contents readily change phase from solid to vapor, with very short duration liquid phase.
For example, 3 methylbutanal, vanillin, and several organic compounds which are known to be readily volatile.
State two characterstics of matter demostred
by
Diffusion
.) Brownian mation
What is the general formula for the homologous series that includes ethene?
Answer:
See below
Explanation:
The common formula of the same alkene series is CnH2n, where n is the quantity of atoms of carbon. Owing to the hydrocarbons of alkenes with at least one double carbon relation, the alkene-like sequence starts with ethen C2H4.
Hope this helps.
The general formula for the homologous series which includes ethene is alkenes.
Alkenes
They are homologous series with the general formula CxH2x.
Where:
x = number of carbon atoms.
Examples are methene with one carbon atom: CH2
Ethene with 2 carbon atoms: C2H4
Propene with 3 carbon atoms: C3H6
More on alkenes can be found here: https://brainly.com/question/7337516
The pH of a solution is 2.0. Which statement is correct?
Useful formulas include [H30+1 = 1070F, FOH-7-10 +0H, PH+pOH = 14, and [H30 [0H-]- 10-14
Answer:
pH + pOH = 14, [H₃0⁺] [0H⁻] = 10⁻¹⁴
Explanation:
When it comes to questions involving pH, the equations used are;
[H₃0⁺] [0H⁻] = 10⁻¹⁴
This equation shows the concentration of hydroxonium ions alongside that of the hydroxide ions.
pH + pOH = 14
If the value of either the pH of the pOH is know,one can calculate the value of the other using this equation.
Answer:
The answer is A. The pOH of the solution is 12.0
Explanation:
The formula for pOH is:
pOH = 14 - pH
We know that the pH value is 2.0 so we plug it in the equation:
pOH = 14 - (2.0)
After simplifying it, we get an answer of 12.0 which is the pOH value.
Hope this helps!
I. Plant cells are formed from fertile soil. II. Cells must function properly for an organism to be healthy III.Cells make up the petals, stem, and leaves of a lily plant. IV. Bacteria are produced from other living bacteria. Which describes the statements that Schwann and Schleiden would make?
Answer:
No. 4
Explanation:
Bacteria are produced from pre existing bacteria
A compound contains 46% Sodium, 12% Carbon and 42% Oxygen. The molecular mass of the compound is 106 u. Draft a table with these data and find the Empirical formula and Molecular formula of this compound. Given that atomic masses are Na=23 u, C=12u and O=16u.
Answer:
Empirical formula is Na₂CO₃
Molecular formula is Na₂CO₃
Explanation:
Percentage compositions of the elements;
Sodium = 46%
Carbon = 12 %
Oxygen = 42%
To determine empirical formula, we calculate the mole ratio first.
mole ratio = % mass/atomic mass; where the atomic masses of the elements are : Na = 23 u, C = 12 u and O = 16 u.
mole ratio: Na = 46/23; C = 12/12; O = 42/16
mole ratio (Na : C : O) = 2 : 1 : 2.6
approximate mole ratio = 2 : 1 :3
Therefore, empirical formula of compound is Na₂CO₃
To determine the molecular formula;
molecular formula or mass = n(empirical formula or mass)
n = molecular mass/empirical mass
molecular mass = 106 u,
empirical mass = 23*2 + 12 + 16*3 = 106 u
then, n = 106/106 = 1
therefore, molecular formula = 1 * (Na₂CO₃) = Na₂CO₃
Why are fictional groups important
Answer:
Functional groups are important in chemistry because they are the portion of a molecule that is capable of characteristic reactions.
Explanation:
Answer:
pls help
Explanation:
Juan puts a pencil into a glass of water. The pencil appears broken at the point where it enters the water. What causes the pencil to look broken? A. The water in the glass absorbs incoming light waves so light cannot pass through the water. B. The light waves traveling through the glass are refracted as the waves pass from air to water. C. The water in the glass changes incoming light waves into a different form of energy. D. The light waves traveling through the glass are reflected by the pencil when it is underneath the water.
Answer:
d
Explanation:
What will it’s change in temperature be?
_______________’c?
Answer:
72.8°C
Explanation:
Step 1:
Data obtained from the question. This include the following:
Specific heat capacity (C) = 0.24J/g°C
Mass (M) = 15g
Heat (Q) = 262J
Change in temperature (ΔT) =..?
Step 2:
Determination of the change in temperature.
The change in temperature, ΔT can be obtained as follow:
Q = MCΔT
262 = 15 x 0.24 x ΔT
Divide both side by 15 x 0.24
ΔT = 262 / (15 x 0.24)
ΔT = 72.8°C
Therefore, the change in temperature, ΔT is 72.8°C
The solubility of a solute and solvent at a given temperature is 30.65 g/100 mL.
How much of the solute could be dissolved in 2 L of the solvent?
Please remember to consider significant figure or precise value rules.
Answer:
613.0 g
Explanation:
2 L = 2000 mL
(30.65 g/100 mL)*2000 mL = 613.0 g
Given:
Solute + solvent = 30.65 g/100 mLSolvent = 2LSolution:
Firstly,
We converted L to mL
2 L = 2 × 1000 mL = 2000 mL [ 1 L = 1000 mL ]
Now,
Solute = 30.65/100 × 2000
= 30.65 × 2000 / 100
= 61,300/100
= 613
A(n)________ can change shape and volume.
Answer:
gas and liquid
Explanation:
right?
Which is more reactive: Magnesium or Potassium?
If 18.0 kJ of energy are applied to 250. grams of water at 37°C, what will be the final temperature
Answer:
54.1°C
Explanation:
Now we have the following parameters from the question;
Heat applied (H)= 18.0×10^3 Joules
Mass of the water(m)= 250g= 0.25Kg
Initial temperature of the water (θ1)= 37°C
Final temperature of the water (θ2)= the unknown
Heat capacity of water (c) = 4200JKg-1
From ;
H= mc(θ2-θ1)
Substituting values appropriately
18×10^3= 0.25 × 4200(θ2-37)
18×10^3 = 0.25 × (4200θ2 - 155400)
18×10^3 = 1050θ2 - 38850
18×10^3 + 38850 = 1050θ2
56850 = 1050θ2
θ2= 56850/1050
θ2= 54.1°C
Which are the reactants in the following reaction?
2 Mg + O2 ---> 2MgO
a)Mg and O
b)Mg and MgO
c)MgO
d)O and MgO
Answer:
The second one is correct
Explanation:
Because reactants are sth that attend in a reaction and can make sth like (MgO) of course in this question. For example in this reaction : H+ClHCl. That H and Cl are reactants
Good luck
what is ⅓ of 21
answer me this please
Answer:
7
Explanation:
1/3 of 21 is also the same as 21/3, which is 21 divided by 3
So the right answer is 7.
please see attached picture for full solution
hope it helps
Good luck on your assignment
Use Hess's Law to determine the enthalpy change (∆H) for the reaction: ClF + F2 → ClF3 Given: 2ClF + O2 → Cl2O + F2O. ∆H=167.4kJ 2ClF3 + 2O2 →Cl2O + 3F2O. ∆H=341.4kJ 2F2 + O2 →2F2O. ∆H=-43.4kJ
Answer:
The enthalpy change (∆H) for the reaction is -108.7 kJ
Explanation:
Hess's law can be stated as: when the reactants are converted to products, the enthalpy change is the same, regardless of whether the reaction is carried out in one step or in a series of steps. Then, Hess's Law states that the enthalpy of one reaction can be achieved by algebraically adding the enthalpies of other reactions.
So, to calculate the ∆H (heat of reaction) of the combustion reaction, that is, the heat that accompanies the entire reaction, you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient ( number of molecules of each compound participating in the reaction) and finally subtract them.
Enthalpy of combustion = ΔH = ∑Hproducts - ∑Hreactants
2 ClF + O₂ → Cl₂O + F₂O ∆H=167.4kJ
Cl₂O + 3 F₂O → 2 ClF₃ + 2 O₂ ∆H= -341.4kJ
The previous equation must be inverted, and the enthalpy value is also inverted, that is, the sign is changed.
2 F₂ + O₂ →2 F₂O ∆H=-43.4kJ
Reactants and products are added or canceled, taking into account that certain substances sometimes appear as a reagent and others as a product, so they are totally eliminated (there is nothing left of them anywhere in the reaction, if the same amount in reagents and products) or partially (this substance remains, in less quantity, only on one side), obtaining:
2 ClF + 2 F₂ → 2 ClF₃
Then, as all the reactants and products have a stoichiometric coefficient of 2, dividend by that number is obtained:
ClF + F₂ → ClF₃
Adding the enthalpies algebraically, and dividing by 2, because to get the "data" reaction you had to multiply by two, you get:
ΔH= [167.4 kJ - 341.4 kJ - 43.3 kJ]÷2
ΔH= -108.7 kJ
The enthalpy change (∆H) for the reaction is -108.7 kJ
Which factor(s) will most likely lower the activation energy of a reaction?
A. Concentration
B. Temperature and Concentration
C. Catalysts
D. Temperature and Catalysts
elements that are anions
Answer:
I hope this will help its not much
Explanation:
help me with 23 fast
Answer:
a salt
Explanation:
compounds are made of molecules but we need to mention the type of compound formed.
Answer:
A salt
Because compounds are made of molecules but we need to mention the type of compound formed.
Please help me complete the following word equations:) also write the balanced equation, full ionic equation, and net ionic equation. Also include the states:)
a) zinc nitrate + calcium sulphide—>
b) potassium + calcium chloride—>
Explanation:
The states may differ depending on the reactions
A 18 g sample of metal is heated to 96°C and placed in a calorimeter containing 21 g of water at an initial temperature of 24°C. After the metal cools in the water bath, the final temperature inside the calorimeter is 26°C. What is the (positive) specific heat of the metal rounded to the HUNDREDTHS place? (hint: final temperatures of metal and water are the same).
Answer:
THE SPECIFIC HEAT OF THE METAL IS 0.14 J/g K
Explanation:
First, write out the variables in the question
Mass of sample = 18 g
Initial temp of metal = 96°C = 96 + 273 = 369 K
Mass of water = 21 g
Initill temp of water = 24°C = 24 + 273 K = 297 K
final temp of water and metal = 26°C = 26 + 273 K = 299 K
temperature change = (
In calorimetry, there is conservation of energy and heat liberated by one is absorbed by the other. That is heat gained is equals to heat lost.
Heat lost by the metal = Heat gained by water
mc ΔT = mc ΔT
18 * C * ( 299 - 369 ) = 21 * 4.2 * ( 299 - 297)
18 * C * -70 = 21 * 4.2 * 2
-1260 C = 176.4
C = 176.4 / 1260
C = 0.14 J/ g K
The specific heat of the metal is hence 0.14 J/g K
An object has a mass of 10 kg. when a net force of 40 n north acts on the object, what is it’s acceleration ?
Answer:
4m/s² north.
Explanation:
Data obtained from the question include the following:
Mass (m) = 10Kg
Force (F) = 40N North.
Acceleration (a) =...?
Force is simply the product of mass and acceleration. It is represented mathematically as:
Force (F) = Mass (m) x acceleration (a)
F = ma
With the above formula, we can obtain the acceleration of the object as follow:
40 = 10 x a
Divide both side by 10
a = 40/10
a = 4m/s²
Since the force was applied in the north direction, the object will also accelerate in the north direction. Therefore, the acceleration of the object is 4m/s² north.
