Solution :
It is given that :
The formula of the compound = [tex]$XBr_3$[/tex]
And that 4.70 g of the sample contains [tex]$4.834 \times 10^{-2}$[/tex] mol of Br.
It means that :
1 mol of [tex]$XBr_3$[/tex] contains = 3 mol of Br
∴ 3 mol of [tex]$Br^-$[/tex] contain in 1 mol of [tex]$XBr_3$[/tex]
[tex]$4.834 \times 10^{-2}$[/tex] mol of [tex]$Br^-$[/tex] contains [tex]$1.576 \times 10^{-2}$[/tex] mol of [tex]$XBr_3$[/tex]
Thus the mol of [tex]$XBr_3$[/tex] = [tex]$1.576 \times 10^{-2}$[/tex] mol
The given mass is = 4.700 g
Therefore, the [tex]$\text{molar mass}$[/tex] of [tex]$XBr_3$[/tex] [tex]$=\frac{\text{mass}}{\text{mol}}$[/tex]
[tex]$=\frac{4.700 \ g}{1.576 \times 10^{-2} \ mol}$[/tex]
= 298.4 g/mol
So [tex]$\text{molar mass}$[/tex] of [tex]$XBr_3$[/tex] = [tex]$\text{molar mass}$[/tex] of X + 3 x [tex]$\text{molar mass}$[/tex] of Br
298.4 g/mol = [tex]$\text{molar mass}$[/tex] of X + 3 x 79.90 g/mol
298.4 g/mol = [tex]$\text{molar mass}$[/tex] of X + 239.7 g/mol
[tex]$\text{molar mass}$[/tex] of X = 58.71 g/mol (since 1 amu = 1 g/mol)
Therefore the atomic mass of the unknown metal = 58.71 g/mol
So the unknown meta is Nickel.
Please help me!!! this is due now
what observation helps a poison ivy plant survive in its environment
Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate the moles of water needed to produce 0.075mol of glucose. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits
Answer: 0.45 moles of water are needed to produce 0.075mol of glucose.
Explanation:
The balanced chemical reaction is:
[tex]6CO_2(g)+6H_2O(l)\rightarrow C_6H_{12}O_6(aq)+6O_2(g)[/tex]
According to stoichiometry :
1 mole of glucose require = 6 moles of [tex]H_2O[/tex]
Thus 0.075 moles of glucose require = [tex]\frac{6}{1}\times 0.075=0.45[/tex] moles of [tex]H_2O[/tex]
0.45 moles of water are needed to produce 0.075mol of glucose.
How many Joules of heat are released from a 400g piece of glass that has been cooled
from 28°C to 6°C? The specific heat for this particular type of glass is 0.664 J/g°C.
please show work.
Answer:
400 × 22 × 0.664 = 5843.2 J
What volume, in milliliters, of a 0.140 M solution of KCl contains 2.65 g of the compound?
Express the volume to three significant figures and include the appropriate units.
Answer:
Calculate moles KCl: 2.55 g / 74.55 g/mol = 0.0342 moles KCl
Volume KCl = 0.0342 mol X (1 L/0.150 mol) = 0.228 L X 1000 mL/L = 228 mL
Explanation:
Volume=288mL
Given:
Molarity=0.140 M
Mass=2.65 g
To find:
Volume=?
Molar mass of KCl = 74.55 g/mol
Firstly, we need to calculate the number of moles of KCl:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Number of moles}=\frac{2.65g}{74.55g/mol} \\\\\text{Number of moles}=0.0355 moles[/tex]
In order to calculate the volume,
[tex]\text{ Volume of KCl} = 0.0342 mol * (1 L/0.150 mol) \\\\\text{ Volume of KCl} = 0.228 L * 1000 mL/L \\\\\text{ Volume of KCl} = 228 mL[/tex]
The volume in mL will be 228mL.
Learn more:
brainly.com/question/15356425
Give two reasons why people should use petrochemicals wisely.
As petrochemicals are originate from petroleum products, it is non-renewable and also can result in pollution so they are used wisely.
What are petrochemicals?Petrochemicals are the chemical byproducts of petroleum refining. Some petroleum-derived chemical compounds are also derived from other fossil fuels, such as coal or natural gas, or renewable sources, such as maize, palm fruit, or sugar cane.
All of this begins with six fundamental petrochemicals: ethylene, propylene, butylenes, benzene, toluene, and xylenes, which are combined with other chemicals and transformed into other materials that improve products.
Concerns are raised not only about the negative environmental impact, but also about the impact on human health.
Many petrochemicals are among the most toxic substances known to man, but they are found in almost everything, from plastics to synthetic fragrances and dyes to fertilizer.
Thus, these are used wisely.
For more details regarding petrochemicals, visit:
https://brainly.com/question/28540307
#SPJ2
320.0 g of NaCl would contain how many formula units? (Molar mass of
NaCl is 58.44 g/mol) *
Answer:
Formula unit = 32.9746×10²³
Explanation:
Given:
Mass of NaCl = 320 g
Molar mass of NaCl = 58.44 g/mol
Find:
Formula unit
Computation:
Formula unit = [Mass of NaCl / Molar mass of NaCl]Avogadro's number
Formula unit = [320 /58.44]6.022×10²³
Formula unit = 32.9746×10²³
#15 need help don’t understand
Calculate the root - mean - square speeds of helium atoms and nitrogen molecules in m/s at 25° C
Answer: a) root - mean - square speeds of helium atom is 43.1 m/s
b) root - mean - square speeds of nitrogen molecule is 16.29m/s
Explanation:
The formula used for root mean square speed is:
[tex]\nu_{rms}=\sqrt{\frac{3RT}{M}}[/tex]
where,
[tex]\nu_{rms}[/tex] = root mean square speed
R = gas constant = [tex]8.314J/Kmol[/tex]
T = temperature = [tex]25^0C=(25+273)K=298K[/tex]
M = atomic mass
a) root - mean - square speeds of helium atom [tex](He)[/tex]
[tex]\nu_{rms}=\sqrt{\frac{3\times 8.314J/Kmol\times 298K}{4g/mol}}=43.1m/s[/tex]
b) root - mean - square speeds of nitrogen molecule [tex](N_2)[/tex]
[tex]\nu_{rms}=\sqrt{\frac{3\times 8.314J/Kmol\times 298K}{28.02g/mol}}=16.29m/s[/tex]
What are a few ways your body maintains homeostasis?(6th grade and its science)
Answer: Internal Temperatures. Similarly, the cardiovascular, integumentary (skin and associated structures), respiratory, and muscular systems work together to help the body maintain a stable internal temperature. If body temperature rises, blood vessels in the skin dilate, allowing more blood to flow near the skin's surface.
Explanation:
You find a 1979 copper penny (pre-1982 pennies are pure copper) in the snow and pick it up. How much heat does the penny absorb as it warms from the temperature of the snow, -5.0∘C to the temperature of your body, 37∘C. Assume the penny is pure copper and has a mass of 3.10 g. (The specific heat capacity of copper is 0.385 J/g∘C.)
Answer:
50.127 J
Explanation:
The following data were obtained from the question:
Initial temperature (T₁) = –5 °C
Final temperature (T₂) = 37 °C
Mass (M) = 3.10 g
Specific heat capacity (C) = 0.385 J/gºC
Heat (Q) absorbed =?
Next, we shall determine the change in temperature. This can be obtained as follow:
Initial temperature (T₁) = –5 °C
Final temperature (T₂) = 37 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 37 – (–5)
ΔT = 37 + 5
ΔT = 42 °C
Finally, we shall determine the heat absorbed. This can be obtained as follow:
Mass (M) = 3.10 g
Specific heat capacity (C) = 0.385 J/gºC
Change in temperature (ΔT) = 42 °C
Heat (Q) absorbed =?
Q = MCΔT
Q = 3.10 × 0.385 × 42
Q = 50.127 J
Thus, the heat absorbed is 50.127 J.
Buffer sol that contain 1 mol NH4Cl and 1mol NH4OH per liter find PH
Answer: what
Explanation:
What is the PH for a solution that has an H+ ion concentration of 1.0x10^-6 M
Answer: POH=8
Explanation:PH = -log( H+concentration)
PH = 6
POH = 14 - PH = 8
who know the song genius?
Answer:
Me
Explanation:
The one with sia??
Pre-Lab Assignment
1.
Describe the following trends in properties of oxides across Period 3.
(a)
(b)
Their appearance.
Their volatility
Their structure.
Their acid-base character
Their conductivity
(d)
Answer:
See explanation
Explanation:
From left to right, the oxides across period 3;
i) Period 3 oxides all appear white in colour. They are all crystalline solids and their melting points decrease from left to right.
ii) The volatility of period 3 oxides increases from left to right across the periodic table
iii) The metallic oxides on the right hand side adopt giant ionic structures. Silicon oxide which is in the middle of the period forms a giant covalent structure. Oxides of other elements towards the right hand side form molecular oxide structures.
iv) The acidity of oxides of period 3 increases from left to right. Metals on the left hand side form basic oxides while non-metals on the right hand side form acidic oxides. The oxide of aluminium in the middle is amphoteric.
v) The oxides of period 3 elements do not conduct electricity. However, the metallic oxides on the lefthand side conduct electricity in molten state. The non-metallic oxides on the right hand side are molecular hence they do not conduct electricity under any circumstance.
Which of the following statements about balanced chemical equations is correct?
A.
The products must contain the same numbers and types of atoms as the reactants.
B.
The products must contain the same arrangement of atoms as found in the reactants.
C.
The products must contain the same numbers but not the same types of atoms as the reactants.
D.
The products must contain the same types but not the same numbers of atoms as the reactants.
Answer:A.
The products must contain the same numbers and types of atoms as the reactants.
Explanation: I think this
Answer:a
Explanation:
What is the Empirical formula of sucrose (C12H22O11) ?
Sucrose is C12H22O11 and here we can not express it as the simplest ration of integers. So its empirical formula is same as that of its molecular formula I.e-C12H22O11.2017年10月31日
Which of the following is a potential exception to cell theory? Choose 1 answer: Fungal spore Asexual reproduction Mitochondria Amoebas
Answer:
Asexual reproduction
Explanation:
Cells are able to re produce themselves without other cells needed. If cells need others to make more then how would that work and plus we wouldn't have the theory of cells existing.
All but one statement below tell why scientists work in groups
A.problems are complex
B.research progress takes a lot of time and money
C.some scientists are lazy and steal the ideas of others
D.research progress occurs in small steps, so many people are needed
Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow. Pb ( N O ₃ ) ₂ (aq) + K I (aq) → ☐⁴⁻ ☐³⁻ ☐²⁻ ☐⁻ ☐⁺ ☐²⁺ ☐³⁺ ☐⁴⁺ 1 2 3 4 5 6 7 8 9 0 ☐₁ ☐₂ ☐₃ ☐₄ ☐₅ ☐₆ ☐₇ ☐₈ ☐₉ ☐₀ + ( ) → ⇌ (s) (l) (g) (aq) NR Pb I N O K Reset
Answer: [tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced molecular equation is:
[tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]
What is climate? What are three things that cause the earths climate?
Answer:
The climate has been caused by many natural factors including changes in the sun emissions from volcanoes variations in Earth's orbit and levels of carbon dioxide. Global climate change has typically occured very slowly over thousands or millions of years .The three causes of the Earth's climate are
Industrial activitiesAgricultural activitiesDeforestationthese are the causes of the Earth's climate.
Climate is a average weather in a given area for a long period of time is called a climate
maybe this might help ur question
Please help me I’m not sure with that
Answer:
i cant see the picture sorry
Explanation:
Which feature of a balanced chemical equation demonstrates the law of
conservation of mass?
A. It has the same types of atoms on both sides of the reaction
arrow.
B. It shows the reactants of a chemical reaction to the left of the
reaction arrow.
C. It shows the products of a chemical reaction to the right of the
reaction arrow
D. It has coefficients to show how much of each substance a
chemical reaction uses.
SUBMIT
Answer:
Another answer is : It has equal numbers of each type of atom in its reactants and products.
Explanation:
I just got it right on A.pex
Given the data from the question, the correct statement is:
It has the same types of atoms on both sides of the reaction arrow (Option A) What is a chemical equation?Chemical equations are representations of chemical reactions using symbols and formula of the reactants and products.
The reactants are located on the left side while the products are located on the right side.
Reactants —> Products
The balancing of chemical equations follows the law of conservation of matter which states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to another.
From the law of conservation of matter, it is evident that the same atoms of the element in the reactants are present in the products.
Thus, we can conclude that the correct answer to the question is: It has the same types of atoms on both sides of the reaction arrow (Option A)
Learn more about chemical equation:
https://brainly.com/question/7181548
What is the estimated life expectancy of tin reserves?
Answer:
chemical reaction hope this helps ;)
Explanation:
please help will give brainiest
Answer:
reaction, reversed, The Law Of Conservation of Mass, mass, rusts, oxygen
Explanation:
HOPE THIS HELPS!
How much heat is required to change 100.0g of ice at 0C into water at 0C?
Answer:
5 degrees required for ice
If 13.5 L of nitrogen gas reacts with 17.8 L of hydrogen gas at STP, according to the following reaction, what mass of ammonia would be produced? N2 + 3 H2 --> 2 NH3 Report your answer with proper significant figures, only a number answer is required, no units needed for this form.
Answer: N5 + H4 and then do 13.5 * 17.8 then solve so 240.3 divided by 9
Your answer is 26.7 Pretty sure
Explanation: (study)
Answer:
Work is all on the paper
If a 130-kg car is traveling at a velocity of 23 m/s, what is the kinetic energy of the car?
Kinetic energy is the amount of energy present in the object due to motion. It is required by the body for action and motion. The kinetic energy of the car is 34385J.
What is kinetic energy?Kinetic energy is a type of energy that is directly proportional to the mass of the object and the square of the velocity. The formula for the kinetic energy can be given as,
[tex]\rm KE = \dfrac{1}{2}mv^{2}[/tex]
Here,
Mass of the car (m) = 130 kg
Velocity of the car (v) = 23 m/s
Substituting values in the equation:
[tex]\begin{aligned}\rm KE &= \dfrac{1}{2}\rm mv^{2}\\\\&= \dfrac{1}{2}\times 130\times (23)^{2}\\\\&= 34385\;\rm J\end{aligned}[/tex]
Therefore, 34385J is the kinetic energy of the car.
Learn more about kinetic energy here:
https://brainly.com/question/13870124
Answer fast please?????????????
Answer:
option a. iron,copper, aluminium.
Calculate the volume of a balloon that can hold 113.4 g of nitrogen dioxide, NO2 gas at STP-
Answer:
55.18 L
Explanation:
First we convert 113.4 g of NO₂ into moles, using its molar mass:
113.4 g ÷ 46 g/mol = 2.465 molThen we use the PV=nRT formula, where:
P = 1atm & T = 273K (This means STP)n = 2.465 molR = 0.082 atm·L·mol⁻¹·K⁻¹V = ?Input the data:
1 atm * V = 2.465 mol * 0.082atm·L·mol⁻¹·K⁻¹ * 273 KAnd solve for V:
V = 55.18 L