Answer:
[tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
Explanation:
Let [tex]x[/tex] denote the number of [tex]\rm H_{2}O[/tex] formula units for every [tex]\rm MgCl_{2}[/tex] formula unit. The formula of the hydrate would be [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex].
Look up the relative atomic mass of each element on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm Br[/tex]: [tex]79.904[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Formula mass:
[tex]\begin{aligned}M({\rm MgBr_{2}}) &= 24.305 + 2 \times 79.904 \\ &= 184.113\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
[tex]\begin{aligned}M({\rm H_{2}O}) &= 2 \times 1.008 + 15.999 \\ &= 18.015\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
The anhydrous compound would be [tex]\rm MgBr_{2}[/tex]. There was [tex]27.21\; \rm g[/tex] of this compound. Calculate the number of moles of formula units in that much of this compound:
[tex]\begin{aligned}n({\rm MgBr_{2}}) &= \frac{m({\rm MgBr_{2}})}{M({\rm MgBr_{2}})} \\ &= \frac{27.21\; \rm g}{184.113\; \rm g \cdot mol^{-1}} \\ &\approx 0.1478\; \rm mol\end{aligned}[/tex].
During heating, [tex]43.19\; \rm g - 27.21\; \rm g = 15.98\; \rm g[/tex] of water [tex]\rm H_{2}O[/tex] escaped from the hydrate. Calculate the number of formula units in that [tex]15.98\; \rm g[/tex] of [tex]\rm H_{2}O\![/tex]:
[tex]\begin{aligned}n({\rm H_{2}O}) &= \frac{m({\rm H_{2}O})}{M({\rm H_{2}O})} \\ &=\frac{43.19\; \rm g - 27.21\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\&= \frac{15.98\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\ &\approx 0.887\; \rm mol\end{aligned}[/tex].
In other words, approximately [tex]0.1478\; \rm mol[/tex] of [tex]\rm MgBr_{2}[/tex] formula units (and hence the same number of moles of [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex] formula units) contain approximately [tex]0.887\; \rm mol[/tex] of [tex]\rm H_{2}O[/tex] formula units. Calculate the ratio between the two:
[tex]\begin{aligned}x &= \frac{n({\rm H_{2}O})}{n({\rm MgBr_2})} \\ &\approx \frac{0.1478\; \rm mol}{0.887\; \rm mol} \approx 6\end{aligned}[/tex].
Hence, the formula of the hydrate would be [tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
a. The atomic mass defines the elemental identity of an atom. b. The atomic number of an element is approximately equal to the number of protons in an atom of that element. c. Helium is the smallest atom and has an atomic number of 1. d. Isotopes of the same element have the same atomic mass.
B
Explanation:
option b is correct because
hydrogen is smallest atom
isotopes of elements have different atomic mass
atom mass have nothing to do with elemental identity
what is element Na in a periodic table
Answer:
Sodium.
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is ²³Na.
Answer:
sodium
atomic mass 22.99
atomic number 11
period 3 group 1 1a
sodium is also an Alkali metal
Explanation:
I have a periodic table on my computer I hope I helped
I need help please!!!!!
Answer:
sorry..,...........
.....
Solids have_____
density and_____
compressibility compared to
liquids.
Answer:
higher density and lower compressibility
1s 2s22p63s23p4
How many valence electrons does this atom have?
2
6
4
12
Answer:
6
Explanation:
How many valence electrons does this atom have?
answer 6
Answer:
6.
Sulphur has 6 valence electrons.
( .°. that's the electronic configuration of sulphur .)
Which medicines are including Chemicals?
Can you help Please!
Answer:
Compounds used as medicines are most often organic compounds, which are often divided into the broad classes of small organic molecules (e.g., atorvastatin, fluticasone, clopidogrel) and "biologics" (infliximab, erythropoietin, insulin glargine), the latter of which are most often medicinal preparations of proteins
How does the chemistry of the ocean change in response to high levels of CO2 in the atmosphere?
Balance in basic solution: O2(g) + Cr³+ (aq) → H₂O2 (1) + Cr₂O7²- (aq)
cr2o72+H2o2-(r3+o2)
Explanation:
r62o72+H2o2-(r3+o2)
If an object is travelling 25.0 meters/second, how far will it travel in 45 minutes?
[tex]\\ \rm\longmapsto Distance=Speed(Time)[/tex]
[tex]\\ \rm\longmapsto Distance=25(2700)[/tex]
[tex]\\ \rm\longmapsto Distance=67500m[/tex]
The object travelling at 25 m/s, will travel a distance of 67500 m in 45 mins.
We'll begin by converting 45 mins to seconds. This can be obtained as follow:1 min = 60 s
Therefore,
45 mins = 45 × 60
45 mins = 2700 sFinally, we shall determine the distance travelled by the object in 2700 s (i.e 45 mins). This can be obtained as follow:Time = 2700
Speed = 25 m/s
Distance =?Distance = speed × time
Distance = 25 × 2700
Distance = 67500 mTherefore, the object will cover a distance of 67500 m in 2700 s (i.e 45 mins)
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How are reactivity and electronegativity related? 1 point)
. An element will be more reactive if it has a very high or very low electronegativity
Elements with lower electronegativity are more reactive than elements with higher electronegativity
Elements with higher electronegativity are more reactive than elements with lower electronegativity
Anmentess reactive it has a very high or very low electronegativity
Elements which have high electron negativity are more reactive than elements with low electron negativity.
This is because elements with high electron negativity will gain more electrons to become more stable.
When electron negativity of an element decrease it becomes more into its element form.
There will be more ionization energy of the elements who have more electron negativity.
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Answer: An element will be more reactive if it has a very high or very low electronegativity.
Is your answer
Determine the empirical formula for compounds that have the following analyses. a. 28.4% copper, 71.6% bromine b. 39.0% potassium, 12.0% carbon, 1.01% hydrogen, and 47.9% oxygen c. 77.3% silver, 7.4% phosphorus, 15.3% oxygen d. 0.57% hydrogen, 72.1% iodine, 27.3% oxygen
Answer:
See explanation
Explanation:
Cu- 28.4/63.5, Br- 71.6/80
Cu- 0.447/0.447, Br- 0.895/0.447
Cu- 1, Br - 2
Empirical formula = CuBr2
b)
K- 39.0/39, C-12.0/12, H- 1.01/1, O- 47.9/16
K= 1, C-1, H- 1. O-3
Empirical formula= KHCO3
c)
Ag- 77.3/108, P-7.4/31, O-15.3/16
Ag-0.716/0.239, P- 0.239/0.239, O-0.956/0.239
Ag-3, P-1, O-4
Empirical formula= Ag3PO4
d)
H-0.57/1, I- 72.1/127, O-27.3/16
H- 0.57/0.57, I- 0.57/0.57, O-1.71/0.57
H-1, I-1, O- 3
Empirical formula= HIO3
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
Es la representación escrita de un cambio químico, se construye con simbología, la cual fue establecida para una mejor interpretación universal de las reacciones.
What process is used to refine aluminum from its ore bauxite?
A. Electrolysis
B. Electrolytic oxidation
C. Voltaic cell processing
D. Smelting
The correct option for the process used to refine aluminum from its bauxite ore is option D.
D. Smelting
The reason why smelting is the correct choice is as follows;
Bauxite is the aluminum ore from which alumina, also known as aluminum
oxide, Al₂O₃, is produced. Bauxite is extracted from the topsoil regions of
some subtropical and tropical regions, and the Bayer process is primarily
then used to produce alumina from the bauxite.
Aluminum is produced from the alumina by an aluminum smelting process
known as the Hall—Heroult electrolytic process which involves the use of a
carbon anode and direct current to produce aluminum by reducing the
aluminum oxide
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SOMEONE PLEASE HELP HURRY
I think the answer is A. I know it's Planet X.
15. Sodium chloride is called an electrovalent compound whereas carbon dioxide is called covalent compound why?
Answer:
NaCl is an electrovalent compound because the sodium and chlorine atoms give one electron from their outermost shells to each other in order to complete their octets
Explanation:
Make me Brain liest plz );
What are the top three sources of US electricity generation?
The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources.
How much does 9.8 liters of ammonia (NH3) weigh at standard temperature and pressure (273 K and 100 kPa)?
A. 13.84 grams
B. 7.44 grams
C. 17 grams
D. 12.91 grams
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write the balanced chemical equation for the following word equation. sodium+sulphate Acidsodium sulphate +hydrogen
Answer:
2NaOH+ H2SO4 → Na2SO4 + 2H2O
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
Answer:
Sodium+sulphate=Na2SO4
Acidsodium sulphate + hydrogen=Na2SO4+H2O
Which of the following substances can be used to neutralize HF? Question 6 options: A) NaOH B) HF C) HCl D) SO2
Answer:
A) NaOH
got it right on the test.
Explanation:
Answer:
NaOH
Explanation:
Which of the following apply to organic compounds. Select all that apply. Organic compounds cannot be synthesized. Organic compounds contain carbon. All organic compounds are products of living things. Organic compounds can be synthesized. All compounds that contain carbon are organic.
Answer:
Organic Compounds CAN BE synthesized
Organic Compounds contain Carbon
I NEED HELP ASAP!!!
All of the following are examples of ways to increase mechanical advantage EXCEPT:
Select one:
a.adding more threads to a screw
b.making a wheel larger than an axle
c.increasing the length of a ramp
d.increase the steepness of a ramp
Identify an element as a metal or a non-metal according to its position in the Periodic
Table
Answer:
Metals on the left of the Periodic Table.
Non-Metals on the top-right, plus Hydrogen.
what is mean by vector
Answer:
A quantity having direction as well as magnitude is called vector.
PLEASE HELP URGENT!!
What is the SI system? What are its benefits?
Answer:
The SI system : The international system of units.
It is a scientific method of expressing the magnitudes or quantities of important natural phenomena.
Benefits of SI system
It is a coherent system of units ( a system based on certain sets of fundamental units )It is a rational system of units ( it assigns only one unit to a particular physical quantity )solution is an example of______mixtures
Answer:
homogeneous mixture must be the answer
If the hydrogen ion concentration, (H+), in a solution is 5.39 x 10-8 M,
what is [OH-]?
A.1.86 x 1021 M
B. 1.86 x 10-7 M
Answer: 1.86*10^-7M
Explanation:
Answer:
B. 1.86 x 10^-7 M
Explanation:
Did you know that before pencil erasers were added on in 1858. people got rid of pencil markings
with white breadcrumbs? Which would erase pencil markings better, an eraser or white bread
crumbs?
Make a hyphotesis plz
Answer:
I guess eraser is better than bread crumbs
Erasers would be better than white bread or crumbs to erase the pencil marks because they would not leave any food marks on the paper and using bread crumbs.
What is an eraser?An eraser is an object of stationary which is used to remove pencil marks from the paper. It is used during writing, when we write something wrong, we could erase or remove the writing from the paper. It is very useful for small children because they usually make mistakes while studying.
Erasers are made from the milk of rubber plants. The milk is collected from the plants, and then it is mixed with chemicals and set down, and then cut into pieces.
Thus, Erasers would be preferable to utilizing bread crumbs or white bread because they would not leave any food stains on the paper after erasing the pencil markings.
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A spontaneous reaction occurs when the sign of free energy is
A: Neutral
B: Zero
C: Positive
D: Negative
What is the temperature of 0.5 moles of water vapor that occupies 120 dm3 and applies a pressure of 15,000 Pa to its container?
A. 433.21 K
B. 5.19 K
C. 7.52 K
D. 108.3 K
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Answer:
The answer is C. 7.52 K
Explanation:
hope it helps
