Identifying Changes of Matter
Which of these are chemical changes in matter? Check all tha
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
Calculate the mols for 4.2g of a Mg
Answer:
0.175mol
Explanation:
Mole of a substance can be calculated using the formula as follows:
number of moles (n) = mass (m) ÷ molar mass (MM)
According to this question, there are 4.2g of Magnesium (Mg).
Molar mass of Magnesium = 24g/mol, hence, the number of moles of 4.2g of Mg is as follows:
n = 4.2g ÷ 24g/mol
n = 0.175mol
Heterogéneo de tres fases y un componente.
A student dissolves 0.75 mol NaCl in 3.55kg water. What is the molality of the resulting solution?
A) 10.32 m
B) 0.211 m
C) 68.2 m
*please help
Answer:
B) 0.211 M
Explanation:
HELP ASAP
Which of these 3 metals ,reacts more vigorously? Sodium, potassium or lithium *
a)Sodium reacts the most vigorously.
b)Potassium reacts the most vigorously.
c)Lithium reacts the most vigorously.
potassium reacts the most vigorously.
Describe the method to make pure, dry crystals of magnesium sulfate from a metal oxide and dilute acid.
Answer:
H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)
Explanation:
We must recall that the oxides of metals are bases. These metal oxides can react with dilute acids to yield salt and water.
Bearing that in mind, we want to obtain magnesium sulfate from a metal oxide and dilute acid.
In this case we need magnesium oxide and dilute sulphuric acid. The reaction occurs as follows;
H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)
A test light with an electrical resistance of 9.00 S2 draws a current of 1.50 A when
it is connected to an electrical source. How much power does the light use?
Answer:
20.25 W
Explanation:
Applying,
P = I²R.................... Equation 1
Where P = Power, I = current drawn by the test light, R = Resistance of the test light
From the question,
Given: I = 1.5 A, R = 9.00 Ω
Substitute these values into equation 1
P = (1.5²)(9)
P = 2.25×9
P = 20.25 W
A 16.4L sample of NO2(S) has a density of 1.89 g/L. What is the mass of the sample NO2(s)?
A) 31.0 grams
B) 14.5 grams
C) 8.68 grams
D) 0.115 grams
Answer:
A. 31.0
Explanation:
Remember the formula [tex]Density = \frac{mass}{Volume}[/tex], or [tex]D=\frac{m}{V}[/tex].
The problem tells us that the density is 1.89 g/L, and that the volume is 16.4 L.(Remember that if the units are in some form of liters, it is volume, similar to how if the units are in grams, it is mass.)
Plug in the numbers for density and volume, and you will get:
[tex]1.89=\frac{m}{16.4}[/tex]
Then, multiply both sides by 16.4 to get:
m = 30.996 g ≈ 31.0 g
Hope this helps!
What is stoichiometry?
Answer:
hope it help u !!!!
Explanation:
Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers
El agua de una alberca requiere de 35.8 gramos de desinfectante (NaClO), por cada 1000 L de agua para mantenerse limpia. El día de hoy el cuidador de la alberca no fue a trabajar y dejó al velador encargado de la adición de desinfectante al agua, pero al velador se le olvidó la cantidad y le agregó 65 g.
Answer:
816L adicionales para mantener la concentración
Explanation:
Cuánta agua debe adicionar el cuidador para que se mantenga la concentración del desinfectante?
El desinfectante, NaClO, idealmente debe estar en una concentración de:
35.8g / 1000L = 0.0358g/L
Como el velador agregó 65g de desinfectante, la cantidad de agua necesaria es:
65g * (1L / 0.0358g) = 1816L de agua son necesarios
Asumiendo que el velador agregó 1000L, el cuidador debe agregar:
1816L - 1000L =
816L adicionales para mantener la concentraciónWhat are 3 things that
happen to your body when you start exercising
regularly?
Explanation:
Weight loss and weight maintenance.
Muscle gain.
Improved mood.
Improved heart health.
At 500K, the equilibrium constant for the reaction N2O4D2NO2 is 1.5 x 10^3. What is the equilibrium constant for the reaction: 6 NO2 D 3N2O4?
Answer:
K = 2.96x10⁻¹⁰
Explanation:
Based on the initial reaction:
N2O4 ⇄ 2NO2; K = 1.5x10³
Using Hess's law, we can multiply this reaction changing K:
3 times this reaction:
3N2O4 ⇄ 6NO2; K = (1.5x10³)³ =3.375x10⁹
The inverse reaction has a K of:
6NO2 ⇄ 3N2O4 K = 1/3.375x10⁹;
K = 2.96x10⁻¹⁰I would appreciate some help please ᕕ( ᐛ )ᕗ
3KOH + FeCl3 → Fe(OH)3 + 3KCl
How many grams of KOH are needed to produce 0.500 moles of KCl?
Answer:
dont know, will let uk in 2 mins
Explanation:
Explanation:
hope this helps you to understand:)
La aparición del microscopio ha permitido la creación de nuevas áreas de estudio, tanto en la___________________________
Answer:
En la mejora de la investigación y la medicina.
Explicación:
La aparición del microscopio ha permitido la creación de nuevas áreas de estudio, tanto en la mejora de la investigación como en la medicina. La invención del microscopio nos permite crecer y desarrollarnos en el campo de la investigación y el estudio. Con este microscopio, los científicos pudieron descubrir la estructura de la célula, así como las partículas subatómicas que están presentes dentro del átomo. Gracias a este microscopio, los científicos pudieron crecer y desarrollarse en el campo de la creación de nuevos medicamentos.
Un elemento X, del grupo I A, reacciona con un elemento Y, del grupo VI A. Señalar cuáles de las siguientes afirmaciones son correctas y cuáles no, justificando en todos los casos:
a) X es un metal
b) Y es un metal
c) La fórmula del compuesto es XY2
d) El compuesto es iónico
Write the nuclear equation for the beta decay
of calcium-45.
Answer:
on https://www.ck12.org/book/peoples-physics-concepts/section/20.1/
Explanation:
it shows for calcium 45 and maybe a possible equation on 3/4th's scroll down?
what is an earthquake's epicenter found
Answer:
an epicenter is where an earthquake first hit
Answer:
The epicenter
Explanation:
The location below the earth's surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. ... These are smaller earthquakes that occur afterwards in the same place as the mainshock.
How does a scientist make two solutions with the same molarity?
O A. By dissolving the same number of moles of each substance in the
same volume of water
B. By dissolving the same number of grams of each substance in the
same volume of water
C. By dissolving the maximum amount of each substance in the
same volume of water
D. By dissolving 1 mole of each substance in enough water to make
sure dissolving is complete
Answer:
a
Explanation:
It's a duh
Explain, in terms of particles, why liquid
iodine does not conduct electricity.
Answer:
Because iodine is a liquid, it has no melting point. Iodine is not an electrical conductor because each molecule consists of two iodine atoms connected by a covalent bond that cannot be stimulated sufficiently to transmit electrical energy.
Explanation:
brainlist???
Explanation:
Because in an aqueous solution of iodine, iodine atoms are joined to each other by simple covalent bonds. Thus, when excitation occurs, the strength of the covalent bond is too weak to be able to transfer electrons, thus lacking the ability to conduct electricity.
Vierte dos líquidos en una pendiente. No sabes qué tipo de sustancias son y necesitas saber cuál es más viscosa. La única herramienta que tienes es un cronómetro. ¿Qué puedes hacer para solucionar este problema?
Answer:
La respuesta está en la explicación
Explanation:
La viscosidad se puede definir como la resistencia al movimiento que presenta un líquido.
Al verter dos líquidos por separado en una pendiente, podrás ver cómo un líquido se tardará más en llegar al final de la pendiente que el otro. Este líquido será EL MÁS VISCOSO.
Así podrás, con el cronómetro, medir el tiempo que cada líquido se tarda en llegar a cierto punto de la pendiente, EL QUE TARDE MÁS SERÁ EL MÁS VISCOSO.
the ending of a compounds name that is made up of three elements,one of which is oxygen
Answer:
—COOH
Explanation:
—COOH, acid group, containing 3 elements, C, carbon, O, oxygen, and H, hydrogen.
the pH of orange juice is 4.0. what is the hydrogen ion concentration in orange juice ASAP PLEASE
pH = 4
- log[H+]= 4
[tex][H+] = {e}^{ - 4} [/tex]
[tex][H+] = 54.6[/tex]
The pH of orange juice 4. The concentration of hydrogen of [tex]10^{-4}[/tex].
What is pHThe pH scale, which originally stood for "potential of hydrogen," is being used to describe the acidity or alkalinity of aqueous solutions.
Calculation of concentration of hydrogen ion by using pH formula.
It can be calculated by using the formula.
pH = -log[[tex]H^{+}[/tex]].
[[tex]H^{+}[/tex]] = [tex]10^{-pH}[/tex]
[[tex]H^{+}[/tex]] = [tex]10^{-4}[/tex]
Therefore, the concentration of hydrogen ion by using pH formula will be [tex]10^{-4}[/tex].
To know more about pH
https://brainly.com/question/15289741
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Is salt pure or impure
Answer:
pure
Explanation:
because there no additional substance
What is the physical state of nitrogen at -200c
The table below gives some characteristics of element Y.
Characteristics of element Y Values
Mass number 11
Number of neutrons in a single atom 6
Average atomic mass (grams/mole) 10.81
What is the identity of element Y?
Answer:
Boron B
Explanation:
According to the periodic table, Boron is the element with atomic mass of approximately 11 [i.e 10.81]
To calculate Neutrons
Neutrons = Mass number - Protons
Number of protons in Boron is same as atomic number which is 5
Thus, N = 11 - 5 = 6
Please solve this question for me.
Answer:
0.0013 moles
Explanation:
moles = volume/ molar volume of gas
=240/24000cm3 (convert dm3 to cm3)
=0.0013
Why can you not create a Punnett square
to determine the height of an individual-
I need to know how to do this but if you could just answer it it's fine
Answer:
im not entirely sure what needs to be done but the 2NH3 is the product and the other half is the reactants .
if any elements are added to others it is the reactants
this is a breakdown of a compound because the arrow always indicates the direction of the reaction .
What does the prefix trans-indicate?
The carbons on either side of the double bond are pointed in opposite directions.
In lab, you calculate the density of an iron rod to be 7.30 g/cm3. The accepted value
for the density of iron is 7.80 g/cm3. What is your percent error?
Answer:
6.41 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 7.80 g/cm³
error = 7.30 - 7.80 = 0.5
We have
[tex]p(\%) = \frac{0.5}{7.8} \times 100 \\ = 6.410256...[/tex]
We have the final answer as
6.41 %Hope this helps you