Answer:
A pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Mixtures are physical combinations of two or more elements and/or compounds.
5 examples of Earth Surface .
Answer:
lithosphere (land)
hydrosphere (water)
biosphere (living things)
atmosphere (air).
Multiple choice (ASAP!)
Answer:
c
Explanation:
oxygen is lost electrons are added in oxidation state is decreased
Answer:
the correct answer is C
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Consider:
2Al (s) + 3Cl2 (g) ----> 2AlCl3 (s) ΔH=-1390.81 kJ
Which of the following correctly describes he magnitude and direction of the enthalpy change when 10.0g of AlCl3 forms?
a. 104.4 kJ, exothermic
b. 52.2 kJ, exothermic
c. 26.1 kJ, exothermic
d. 52.2 kJ, endothermic
e. 26.1 kJ, endothermic
Answer:
The answer is B.
Explanation:
1 mole of AlCl3 = 27 + 3*35.5 grams = 133.5 grams
1 mole / 133.5 = x / 10 Cross multiply
133.5 x = 1 * 10
x = 10 / 133.5
x = 0.0749 moles
Delta H when written the way it is, is on the left side and since it is negative, the reaction must give away 1390.81 kj. The reaction is exothermic.
So now you get the answer between AB and C by setting up a ratio.
2/0.0749 = -1390.81 / x Cross multiply
2x = 0.0749 * -1390.81
2x =- 104.18 Divide both sides by 2
2x//2 = -104.18 / 2
x = -52.09
B
How many molecules of carbon dioxide and how many molecules of water would be produced from 4 molecules of methane (CH4) reacting with 8 molecules of oxygen (O2)
Answer:
4
Explanation:
water would be produced from 4 molecules of methane (CH4) reacting with 8 molecules of oxygen (O2)
The products of the combustion of hydrocarbon are 4 molecules of carbon dioxide and 8 molecules of water.
What is the combustion reaction?A combustion reaction can be described as a reaction that produces fire and takes place at a high temperature. It is an exothermic reaction as well as a redox reaction that usually takes place between a fuel and mostly oxygen gas.
Examples of Combustion Reactions such as during the combustion of 4 molecules of methane reacting with 8 molecules of oxygen gas to give carbon dioxide and two molecules of water.
[tex]4CH_4 + 8O_2\longrightarrow 8H_2O + 4CO_2[/tex]
Oxygen is the essential reactant for combustion because the combustion is not possible in the absence of oxygen. Complete combustion takes place when a fuel burns completely to produce heat with oxygen and carbon dioxide.
The burning of wood fuels in the presence of air is an example of combustion. The carbon present in wood reacts with oxygen gas in the air to liberate heat and form gaseous products.
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Elements in the alkaline earth metal family of the periodic table
have
electronegativity values than elements in the
halogen family of the periodic table.
Answer:Lower
Explanation:
( just had the question on ck12.)
Elements in the alkaline earth metal family of the periodic table have lower electronegativity values than elements in the halogen family of the periodic table as they have less electrons in their valence shell.
What is periodic table?Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
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Can water molecules form ions by
themselves?
1. The average temperature in Addis Ababa, during the summer, is about 25°C. What is the equivalent Kelvin temperature?
Answer:
25 + 273= 298k.
Explanation:
I guess it's correct answer
The equivalent Kelvin temperature is 298 K.
What is temperature?Temperature is defined as a measurement of an object's or substance's warmth or coolness in relation to a standard value.
It can also defined as the feature of matter that represents the amount of energy of motion of its constituent components.
Temperature scale is defined as a method of indicating or measuring temperature with respect to a beginning point (0 or zero) and a unit of measurement.
Temperature scale is also defined as a way of calibrating the physical quantity temperature in metrology.
Usually there is three types of temperature scale is used.
Celsius scaleKelvin scaleFahrenheit scaleThus, the equivalent Kelvin temperature is 298 K.
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can anyone heelp me pls pls
Answer:
Lotion=liquid
suspension=semisolid
capusule=solid
Explanation:
write the electronic configuration of iron in fecl2 and fecl3
Ferrus is a transition metal.
FeCl_2
Valency of Fe is 2 .Hence Z=26-2=24Electronic configuration is given by
[tex]\\ \sf\longmapsto [Fe]^{2+}=1s^22s^22p^63s^23p^64s^23d^4[/tex]
FeCl_3
Valency of Fe is 3Hence Z=26-3=23Electronic configuration is given by
[tex]\\ \sf\longmapsto [Fe]^{3+}=1s^22s^22p^63s^23p^64s^23d^3[/tex]
A particular beer is 65.0% ethanol by volume . If a single bottle of beer contains a total of 750.0 mL of beer, what volume, in mL of ethanol (C₂H₆O), are present in the bottle?
SHOW CONVERSION
The volume in mL of ethanol (C₂H₆O) present in the bottle is 487.5L
HOW TO CALCULATE VOLUME OF ETHANOL:
According to this question, a particular beer is 65.0% ethanol by volume. This means that the beer contains 65/100 of ethanol. If a single bottle of beer contains a total of 750.0 mL of beer, the volume of ethanol in the bottle is calculated as follows:= 65/100 × 750= 65 × 7.5= 487.5mLTherefore, volume in mL of ethanol (C₂H₆O) present in the bottle is 487.5LLearn more at: https://brainly.com/question/8725232?referrer=searchResults
If the atomic mass of an atom is 16 and its atomic number is 7. how many
neutrons does it have?
Answer:
8
Explanation:
Which property describes a material's ability to conduct heat?
What does the phrase “breaking in” mean as it is used in the passage?
A.
In the first instance, it means "to make something come apart," and in the second instance, it means "to stop doing something."
B.
In the first instance, it means "to enter without permission," and in the second instance, it means "to make softer through use."
C.
In the first instance, it means "to stop doing something," and in the second instance, it means "to make something come apart."
D.
In the first instance, it means "to make softer through use," and in the second instance, it means "to enter without permission."
Answer:
D
Explanation:
It means entry by force.
Suppose you did the lab and someone came and said your unknown acid sample was
actually HCl instead of H2SO4. Everything else remains the same; the standard acid was H2SO4,
the base was NaOH. What would change in your final calculation of the unknown acid
concentration
Answer:
H2SO4
Explanation:
because it's not more acidic
Both sulfuric acid and hydrochloric acid are potent acids, but hydrochloric acid is stronger. Because HCl is monoprotic and H2SO4 is diprotic, they differ mostly in their acid types.
Can HCl be substituted for H2SO4?Instead of using hydrochloric acid, sulphuric acid (H 2 SO 4) is preferred because: This acid is commonly utilized for a variety of neutralization reactions. Sulphuric acid is more potent than all other acids and is also simpler and safer to use. Even if there is a risk for negative reactions, they are uncommon.
The majority of the time because it is for a redox reaction or titration in which HCl would react to produce chlorine on its own. You could use phosphoric or sulfuric acid.
In this situation, H 2 SO 4 is preferable to HCl. Due to the considerable acidity of H 2 SO 4, the solution is made to be more acidic than HCl. As a result, the findings of titration using H 2 SO 4 are more precise. H 2 SO4 generates two hydronium ions, whereas HCl only generates one.
It shows how many protons split apart to create hydronium ions. The acid will be more potent the lower the pKa value. Therefore, we can conclude that HCl is more acidic than H2S O 4.
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the class of organic compound below contains a carbonyl group as a part of its structure?
Aldehydes and Ketones. Aldehydes and ketones are classes of organic compounds that contain a carbonyl (C=O) group.
that's the correct answer
can I get brainilest
Please help! I will give 100 pts and brainliest if it is good.
Answer:
group 1 element 6
group 2 element 3
group 11 element 1
group 14 element 2
group 17 element 4
group 18 element 5
Explanation:
Answer:
Explanation:
group 1 element 6
group 2 element 3
group 11 element 1
group 14 element 2
group 17 element 4
group 18 element 5
Synthetic reactions in Citric Acid Cycle
★ « Synthetic reactions in Citric Acid Cycle » ★
The overall reaction for the citric acid cycle is as follows: acetyl-CoA + 3 NAD+ + FAD + GDP + P + 2H2O = CoA-SH + 3NADH + FADH2 + 3H+ + GTP + 2CO2. Many molecules in the citric acid cycle serve as key precursors for other molecules needed by cells.hope it is
Low tides are located at___
A an C
A an B
B an D
Answer: A and C
Explanation:
Low tides occur in locations at 90 degree angles to the moon. Tidal cycles have the same length as the lunar day, 24 hours and 50 minutes. In this time span, most locations will experience two high tides, when the location is close to and far from the moon, and two low tides. Sides A and C are angled 90 degrees from the moon.
Hence, low tides are located at A and C.
Answer:90 degree angles to the moon.
Explanation:
which among the materials have a varying amount of components are they compounds or mixtures
Answer:
Matter can be broken down into two Zalo categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.
In which species does sulphur have the more negative oxidation number? Answers: A. H2S B. S8 (elemental form of sulphur) C. H2SO3 D. K2SO4
Answer:
H2S
Explanation:
the oxidation number of S is -2.
State TRUE or FALSE : Synthetic fibers resists fire.
All fabrics will burn, but some are more combustible than others.
hope it helps
If the number of neutrons in the nucleus of the atom is 41, and the atomic number is 40, what is the mass number of that atom
If the number of neutrons in the nucleus of the atom is 41, and the atomic number is 40, the mass number of that atom will be 81
What is mass number?Mass number is the sum of the number of protons which is the atomic number and neutrons of an atom.
It is represented using the letter ‘A.’
How to calculate the mass numberMass number = atomic number + neutrons
We have the atomic number as 40 and the number of neutrons as 41
The mass number = 40 + 41 = 81
Therefore, the mass number of the atom will be 81
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High temperatures inside Earth form
melted rock.
fossils.
soil.
minerals.
Answer:
minerals
Explanation:
Hope this helps
When excess potassium hydroxide and H2SeO3 react whats the net ionic reaction for the acid-base rxn
The required net ionic equation is; 2H^+(aq) + 2OH^-(aq)-----> 2H2O(l)
The molecular reaction equation is;
H2SeO3(aq) + 2KOH(aq) -----> K2SeO3(aq) + 2H2O(l)
The complete ionic equation is;
2H^+(aq) + SeO3^2-(aq) + 2K^+(aq) + 2OH^-(aq)-----> 2K^+(aq) + SeO3^2-(aq) + 2H2O(l)
Net ionic equation;
2H^+(aq) + 2OH^-(aq)-----> 2H2O(l)
We can clearly see that this is a neutralization reaction hence water is the product of the net ionic equation.
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what happens when co2 dissolves in water
How many molecules of NaCl are there per mL of the solution?
Explanation:
Nacl is an ionic compound, so there are no molecules only formula units please mark me brainlistDetermine the number of moles in 3.13 × 10²³ formula units of MgCl₂.
Answer:
0.52 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.13 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{3.13}{6.02} \\ = 0.519933[/tex]
We have the final answer as
0.52 molesHope this helps you
A flask of water is sealed with a balloon and heated to various temperatures on a hot plate
Answer:
What is the question?
Explanation:
You just gave a statement.
Answer:
it will increase
Explanation:
22.2 g of LiCiO4:3H2O in 125 mL of solution
Express your answer in moles per liter to three significant figures.
What is the Molar Mass?
Answer:
Molarity: concentration measured by the number of moles of solute per liter of solution 3)
Explanation:
According to molar concentration, molarity of solution is 1.104 moles per liter and molar mass is 160.437 g/mole.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.
Molarity of solution is obtained as, 22.2/160.437×1/0.125=1.104 moles per liter.Molar mass of LiClO₄.3 H₂O is 160.437 g/mole.
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the pH of soil X is 7.5 while that of soils Y is 4.5 which of the two coils should be treated with powered talked to adjust its PH
Answer:
Soils Y
Explanation:
• The soils with lower pH are acidic so they react readily with powdered.
[tex].[/tex]
Answer:
SOIL Y
the soil with lower ph are acidic