Answer:
Magnesium Chloride is used as a precursor magnesium metals.
Explanation:
1125 J of energy is used to heat 250 g of iron to 55 °C. The specific heat capacity of iron is 0.45 J/(g·°C).
What was the temperature of the iron before it was heated?
55 °C
55 °C
35 °C
35 °C
45 °C
45 °C
20 °C
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
What amount of SeC16 is needed to produce 4.45 mol of chlorine gas in the
reaction Seclo +0 218) —SeO, +3Cl2te)?
2.85 mol
0.95 mol
5.70 mol
8.55 mol
1.49 mol
Answer:
1.48 moles of SeCl6 are needed
Explanation:
Based on the reaction:
SeCl6 + O2 → SeO2 + 3Cl2
1 mole of SeCl6 reacts producing 3 moles of Cl2.
To solve this question we need to use the conversion factor:
1mol SeCl6 = 3mol Cl2
As we want to produce 4.45 moles of Cl2, we need:
4.45 mol Cl2 * (1mol SeCl6 / 3mol Cl2) =
1.48 moles of SeCl6 are neededThe number of joules required to heat one gram of a substance one degree Celsius is _____.
endothermic
temperature
exothermic
specific heat capacity
4. Magnesium is the limiting reactant in this experiment. Calculate the theoretical yield of MgO for each trial.
5. Determine the percent yield of MgO for your experiment for each trial.
6. Determine the average percent yield of MgO for the two trials.
Answer: The average percent yield of MgO is 98.59 %.
Explanation:
The chemical equation follows:
[tex]2Mg(s)+O_2(g)\rightarrow 2MgO(s)[/tex]
For Trial 1:The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of Mg = 0.411 g
Molar mass of Mg = 24.3 g/mol
Plugging values in equation 1:
[tex]\text{Moles of Mg}=\frac{0.411g}{24.3g/mol}=0.0170 mol[/tex]
By the stoichiometry of the reaction:
If 2 moles of Mg produces 2 moles of MgO
So, 0.0170 moles of Mg will produce = [tex]\frac{2}{2}\times 0.0170=0.0170mol[/tex] of MgO
We know, molar mass of [tex]MgO[/tex] = 40.3 g/mol
Putting values in equation 1, we get:
[tex]\text{Mass of }MgO=(0.0170mol\times 40.3g/mol)=0.685g[/tex]
The percent yield of a reaction is calculated by using an equation:
[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)
Given values:
Actual value of the product = 0.675 g
Theoretical value of the product = 0.685 g
Plugging values in equation 1:
[tex]\% \text{yield}=\frac{0.675g}{0.685g}\times 100\\\\\% \text{yield}=98.54\%[/tex]
Hence, the % yield of the product is 98.54 %
For Trial 2:Given mass of Mg = 0.266 g
Molar mass of Mg = 24.3 g/mol
Plugging values in equation 1:
[tex]\text{Moles of Mg}=\frac{0.266g}{24.3g/mol}=0.011 mol[/tex]
By the stoichiometry of the reaction:
If 2 moles of Mg produces 2 moles of MgO
So, 0.011 moles of Mg will produce = [tex]\frac{2}{2}\times 0.011=0.011mol[/tex] of MgO
We know, molar mass of = 40.3 g/mol
Putting values in equation 1, we get:
[tex]\text{Mass of }MgO=(0.011mol\times 40.3g/mol)=0.443g[/tex]
The percent yield of a reaction is calculated by using an equation:
[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)
Given values:
Actual value of the product = 0.437 g
Theoretical value of the product = 0.443 g
Plugging values in equation 1:
[tex]\% \text{yield}=\frac{0.437g}{0.443g}\times 100\\\\\% \text{yield}=98.64\%[/tex]
Hence, the % yield of the product is 98.64 %
Average of a measurement is calculated by given formula:
[tex]Average=\frac{M_1+M_2}{2}[/tex]
where,
[tex]M_1[/tex] = percentage yield for Trial 1 = 98.54 %
[tex]M_2[/tex] = percentage yield for Trial 2 = 98.64 %
Putting values in above equation, we get:
[tex]Average=\frac{98.54+98.64}{2}=98.59\%[/tex]
Hence, the average percent yield of MgO is 98.59 %.
You mix the sample discussed in the previous two questions with another sample, which you know to be pure acetylsalicylic acid. You grind the mixture thoroughly with a mortar and pestle, and do a melting point determination on the mixed product. You now observe melting over a range of 127 to 133 C. Now what conclusions can you reach regarding the original product
Answer:
Having high melting point.
Explanation:
The original product has high melting point as compared to the mixture product because in the original product, the element is present in its pure state and we know that pure substances have high melting point as compared to mixture substances due to the presence of strong intercellular forces between them which is hard to break so that's why we can say that the original product has high melting point.
A 100 g sample of potassium chlorate, KCIO3(s), is completely decomposed by heating:
2 KCIO3(s) 2 KCl(s) + 3 O2(g)
The oxygen is collected at 89 kPa and 23°C. Calculate the volume, in litres, of oxygen that would be
produced during the decomposition of this sample.
what is the reactant(s) in the chemical equation below
3CO(g) + Fe2O3(s) 2Fe(s) + 3CO2(g)
Answer:
the reactants are carbon dioxide ,iron, oxygen
Teniendo en cuenta la imagen anterior responde las siguientes preguntas:
1. ¿Cuál es la tendencia general de la electronegatividad a lo largo de un periodo? a. Aumentar
b. Disminuir
c. La electronegatividad es igual en todos
d. no hay ninguna tendencia
2. Ordene los átomos siguientes de menor a mayor electronegatividad: Li, Ca, C y Se a. Li
b. Se
c. Ca
d. Se
3. ¿Cuál de los átomos siguientes es el que posee mayor potencial de ionización? a. P
b. Sb
c. As
d. N
4. De las siguientes definiciones, ¿Cuál se acerca más a lo que es la electronegatividad? a. Es la tendencia relativa que presenta un elemento a atraer hacia si electrones b. Es la tendencia relativa de un átomo en estado gaseoso a repeler los electrones c. es la carga negativa que representa una unión
d. es la diferencia entre el potencial de ionización y la afinidad electrónica de un elemento. rapido es para hoy
1. La tendencia general de la electronegatividad durante un período es que la electronegatividad aumenta durante un período
La opción correcta es a. Incremento
Razón
El número de electrones de valencia aumenta durante un período, por lo
que aumentar la tendencia del átomo a lograr la estructura de octeto
estable requiriendo atraer (cada vez menos a medida que avanzamos por
el período desde la izquierda a la derecha) compartieron electrones
cuando se forman enlaces, lo que aumenta electronegatividad
2. El orden de electronegatividad creciente es Li → Ca → C → Se
Razón
La electronegatividad aumenta a lo largo del período y disminuye en el grupo.
Las ubicaciones de los elementos dados son;
Litio, Li; Grupo 1 período 2 Calcio, Ca; Grupo 2 período 4 Carbono, C; Grupo 14 período 2 Selenio Se; Grupo 16 período 4Primero escribimos los elementos con los números de grupo más altos,
que son Se y C, después de lo cual tenemos Ca, luego Li, por lo tanto, en
orden creciente, obtenemos;
Li → Ca → C → Se
3. La opción correcta es d. N (nitrógeno)
Razón
El potencial de ionización representa la energía necesaria para eliminar un electrón de un átomo.
El potencial de ionización disminuye en un grupo y aumenta a lo largo de un período de izquierda a derecha.
Tenemos;
Fósforo, P; Grupo 15 período 3 Antimonio, Sb; Grupo 15 período 5 Arsénico, As; Grupo 15 período 4 Nitrógeno, N; Grupo 15 período 2Por lo tanto, el elemento con mayor potencial de ionización es aquel que se encuentra en la posición más alta en el grupo 15 entre los elementos dados, que es el nitrógeno, N
4. La opción correcta para la definición de electronegatividad es la opción (a);
un. Es la tendencia relativa de un elemento a atraer electrones hacia sí mismo.
Razón
La electronegatividad es la capacidad relativa de un elemento dado para atraer electrones compartidos hacia sí mismo.
Por lo tanto, la opción correcta es a. es la tendencia relativa de un elemento a atraer electrones hacia sí mismo
Obtenga más información sobre la electronegatividad y la energía de ionización aquí;
https://brainly.com/question/13961537
hii pls help me to balance the equation thanksss
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\color{gold}{\sf{2SO_{2}(g) + O_{2}(g)\dashrightarrow 2SO_{3}(g)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\sf {2SO_2\atop Sulphur\:DiOxide}+{O_2\atop Oxygen}\longrightarrow {2SO_3\atop Sulphur\:trioxide}}[/tex]
On reactant side:-Sulphur=2atomsOxygen=6atomsOn products side:-Sulphur=2atomsOxygen=6atomsHence balanced.
how would you detect sulphur in organic compounds
Answer:
sodium fusion is changed to sodium sulphide if sulphur is present in the compound
Having a control group is important when doing an investigation why?
Answer:to help understand the stuff more
Explanation:
How can you calculate the instantaneous rate of a reaction from a graph of concentrations over time?
Select the correct answer.
Which statement accurately describes natural selection?
A.
It ensures that 100 percent of beneficial traits will pass on to the next generation.
B.
It ensures that all individuals with harmful traits are unable to reproduce.
C.
Individuals with beneficial traits are more likely to successfully reproduce than those with harmful traits.
D.
Individuals are all equally likely to successfully reproduce, but the genome will mutate to erase harmful traits.
Answer:
D .
Explanation:
Individuals are all equally likely to successfully reproduce, but the genome will mutate to erase harmful traits.
I need help on this question asap!
You are in a lab and you use 11.50 g of Na(s) to react with Cl(g). Below is the reaction that happens from this.
Na + Cl2 → NaCl
Your percent yield is 95%. From this info what is the actual yield?
Answer:
27.79 g to the nearest hundredth.
Explanation:
2Na + Cl2 ---> 2NaCl
Using the molar masses , the theoretical yield is:
46 g of Na yields 46 + 35.5*2 g NaCl
46 g ---> 117 g NaCl so
11.5 g ----> 117 * 11.5 / 46 g NaCl
But, as the yield is 90%
the actual yield is 0.95 * 117 * 11.5 / 46
= 27.79 g.
Which of these solutions is acidic?
Answer:
Option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).
Explanation:
To know if a solution is acidic we need to calculate the pH and it must be lower than 7. A value of pH equal to 7 is a neutral solution and a solution with a pH value higher than 7 is a basic solution.
a. For the [OH⁻] = 7.0x10⁻⁹ M we have:
[tex] pOH = -log[OH^{-}] = -log(7.0 \cdot 10^{-9}) = 8.15 [/tex]
Now, the pH is:
[tex] pH + pOH = 14 [/tex]
[tex] pH = 14 - pOH = 14 - 8.15 = 5.85 [/tex]
This solution is acidic (pH < 7)
b. [H₃O⁺] = 8.5x10⁻⁸ M
[tex] pH = -log(8.5 \cdot 10^{-8}) = 7.07 [/tex]
This is not an acidic solution. Is a neutral one (pH around to 7).
c. [OH⁻] = 2.5x10⁻⁶ M
[tex] pOH = -log[OH^{-}] = -log(2.5 \cdot 10^{-6}) = 5.60 [/tex]
Then, the pH is:
[tex]pH = 14 - pOH = 14 - 5.60 = 8.40[/tex]
Hence, this is not an acidic solution. It is basic (pH > 7).
Therefore, option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).
I hope it helps you!
Cuales son los tipos de yemas
The process during which cells of the body harness energy from food consumed by a living organism is ______________________.
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be
Options:
814 g
0.125 g
0.278 g
337 g
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
How to calculate mass?The mass of a substance can be calculated by multiplying the number of moles by its molar mass.
However, the number of moles of helium must be calculated as follows:
PV = nRT
Where;
P = pressureV = volumen = no of molesR = gas law constantT = temperature0.985 × 0.785 = n × 0.0821 × 301
0.773 = 24.7n
n = 0.773 ÷ 24.7 = 0.031moles
mass of He = 0.031 × 4 = 0.125g
Therefore, the number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
Learn more about mass at: https://brainly.com/question/19694949
#SPJ6
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
Water is super soluble and this solubility is incredibly helpful for life. Tell me how this solubility helps maintain different processes when it comes to life.
Answer: Water is SUPER soluble and regarded as an universal solvent because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions.
Explanation:
WATER is a substance which is composed of the elements such as hydrogen and oxygen that are combined in the ratio of 2:1. The physical properties of water include:
--> it is a colourless, odourless and tasteless liquid and
--> the boiling point of water is 100°C(this is due to the presence of hydrogen bonding).
The solubility of a solute in a solvent at a particular temperature is the maximum amount of solute in moles or grams that will saturate 1000 dm³ or grams of the solvent.
Water is regarded as a universal solvent BECAUSE it is capable of dissolving many substances. This solubility helps maintain different processes in life such as acting as the solvent which helps cells transport and use substances like oxygen or nutrients.
Organisms do not adapt as a result of competition for resources.
Answer:
The given statement is False.
The organisms adapt as a result of competition for resources. Different places have different organisms suited for that particular places.
The animals living at a particular place compete for the resources available and the nature selects the organism that has won the competition for resources.
The organisms are evolved as a result of competition for resources
Answer:
I just wanted to say the other person is totally right.
this statement is false.
Chemistry!! Help me! And explain step by step!
1st part is ure answer --> 2M
Given mass -> 58 grams
mass of NaCl -> 58.44 approx -> 58 any
moles given-> 1 moles
[tex]Molarity = \frac{moles}{vol \: in \: lts} [/tex]
[tex]Molarity = \frac{1}{0.5} = \frac{10}{5} \\Molarity = 2M[/tex]
ASAP
Which of the following describes a characteristic of water that makes it cohesive in nature?
A - It has a partial negative charge on hydrogen and a partial positive charge on oxygen.
B - It has a linear molecular structure with H-O-H arranged in a straight line.
C - It has a vast electronegativity difference between its constituent atoms.
D - It requires a high amount of heat to raise or drop its temperature.
The answer is C.
The vast difference in electronegativity of the oxygen and hydrogen in water, the O-H bond is polar.
The characteristic of water that makes it cohesive in nature is that It has a vast electronegativity difference between its atoms. So, option C is correct one.
Why water is cohesive in nature?The water molecule contains two hydrogen atoms and oxygen atom.
The electronegativity of hydrogen atoms and oxyegen atom is 2.1 and 3.44
Due to high electronegativity of oxygen ,it can attract the bonded pair of electron of hydrogen and form a strong bond and make it cohesive in nature.
What are major characteristics of water?The water molecule have unique characteristics among all some are given below.
Water is polar, with partial positive charge on two hydrogen and partial negative charge on one oxygen.
Water is act as solvent and dissolves the polar and ionic substance.Water has high heat of vaporization.Water has cohesive and adhesive properties.Water has high heat capacity.learn about water molecule Here,
brainly.com/question/26529979
#SPJ2
HELP PLEASE 15 POINTS
The rate law for a reaction is found to be rate = k[X]4. By what factor does the rate increase if [X] is doubled?
Heat transfer takes place when:
A. there is a temperature difference.
B. conduction or convection occurs, but not radiation.
OC. thermal energy is present.
D. None of these
Answer:
A. There is a temperature difference
Explation:
Whenever there is a temperature difference, heat transfer occurs. Heat transfer may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice chest.
Answer:
A.) there is a temperature difference
Explanation:
I got it correct on founders edtell
What effect does temperature have on reaction rate?
A. An increase in temperature does not change the reaction rate,
B. An increase in temperature keeps the reaction from stopping.
C. An increase in temperature speeds up the reaction rate.
D. An increase in temperature slows the reaction down.
An example of basic research is A) the development of new plastics that can be recycled. B) the study of the relationship between the amount of automobile emissions gases in the atmosphere and the decomposition of atmospheric ozone. C) the study of the composition of the atom. D) the design of new batteries for electric cars. E) the study of natural compounds in sea animals to look for new molecules that can be used for medicine.
Answer:
C) the study of the composition of the atom.
Explanation:
A research can be defined as a systematic investigation or careful consideration of study with respect to a particular problem using scientific methods such as collection of data, documenting critical information, analysis of data, and the establishment of facts in order to reach new conclusions.
Similarly, a basic research is an approach to research that's typically theoritical and it's aimed at developing a theory, searching for the truth or gain a better understanding about a phenomenon, subject, or basic laws on nature.
In this context, an example of basic research is the study of the composition of the atom.
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
What is the formula for the compound iodine trichoride?
Answer:
Cl 3 I
Explanation:
Molecular Weight. 233.36. Appearance. Red-orange to brown powder or chunks. Melting Point. 63 °C
PLZ HELP What human body system includes the stomach, intestines, and teeth?
A. Respiratory system
B. Digestive system
C. Skeletal system
D. Muscular system SUBMIT
Answer:
B
Explanation:
the digestive system
Enolase, an enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate: Group of answer choices demonstrates a base-catalysis step, where a proton is removed from the substrate. demonstrates an acid-catalysis step, where a proton is added to the substrate. requires two Mg2 cofactors and as such demonstrates metal-ion catalysis. stabilizes the intermediate and transition
Answer:
Requires two Mg²⁺ cofactors and as such demonstrates metal-ion catalysis
Explanation:
Electrostatic catalysis or metal ion catalysis is a catalytic mechanism that makes use of metalloenzymes, such as enolase along with a metal ion which is bound tightly, including, Mo⁶⁺, Ni³⁺, Co³⁺, Mn²⁺, Zn²⁺, Cu²⁺, and Fe²⁺, to undertake a catalysis
For maximal activity, enolase requires the presence of 2 equivalent metal ions in each site which is active
Therefore, the correct option is; requires two Mg²⁺ cofactors and as such demonstrates metal-ion catalysis
