1. Which of the following does NOT indicate that a chemical change may have taken place?
A. fracture formation
B. gas production
C. precipitate formation
D. energy transfer
2. What happens to matter during a chemical reaction?
A. matter is neither destroyed or created.
B. some matter is destroyed
C. some matter is created
D. some matter is destroyed and some is created.
convert 1.75 × 1024 atoms of carbon to moles of carbon.
Answer: The number of moles of carbon is 2.90 mol.
Explanation:
We are given:
Number of atoms of carbon = [tex]1.75\times 10^{24}[/tex]
According to mole concept:
[tex]6.022\time 10^{23}[/tex] number of atoms are contained in 1 mole of an element.
So, [tex]1.75\times 10^{24}[/tex] number of atoms will be contained in = [tex]\frac{1}{6.022\times 10^{23}}\times 1.75\times 10^{24}=2.90mol[/tex] of carbon.
Hence, the number of moles of carbon is 2.90 mol.
Which set of coefficients would balance the following chemical equation? H3PO4 + RbOH → H2O + Rb3PO4
Answer:
The balanced equation is:
[tex] H_3PO_4 + 3 RbOH \longrightarrow 3 H_2O +Rb_3PO_4[/tex]
Explanation:
Hi, step by step:
1) Balance the Rb:
[tex]H_3PO_4 + 3 RbOH \longrightarrow H_2O +Rb_3PO_4[/tex]
2) Balance the phosphate:
[tex]1 H_3PO_4 + 3 RbOH \longrightarrow H_2O +Rb_3PO_4[/tex]
3) Balance the water:
[tex]1 H_3PO_4 + 3 RbOH \longrightarrow 3 H_2O +Rb_3PO_4[/tex]
Help meh plz!!!
Which of these systems is responsible for removing waste?
A.endocrine system
B.lymphatic system
C.digestive system
D.excretory system
How many grams of ammonia (NH3) are produced if 4 grams of hydrogen gas (H2) reacts with excess nitrogen gas (N2) according to the chemical equation below:
3 H2 + N2 à 2 NH3
2.43 g
4.86 g
11.33 g
22.66 g
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QUESTION 6
Identify the limiting reactant if 5 g of N2 is allowed to react with 5 g of H2 according to the chemical equation given below. Determine the theoretical yield of the product NH3.
3 H2 + N2 à 2 NH3
limiting reactant is H2 ; theoretical yield = 6.07 g of NH3
limiting reactant is H2 ; theoretical yield = 28.33 g of NH3
limiting reactant is N2 ; theoretical yield = 6.07 g of NH3
limiting reactant is N2 ; theoretical yield = 28.33 g of NH3
1 points Save Answer
QUESTION 7
For a given chemical reaction, the chemist determined the theoretical yield of product is equal to 15.1 grams. In the laboratory, the chemist only recovered 8.25 grams of product (the actual yield). Calculate the percent yield.
32.7%
48.9%
54.6%
82.3%
Final answer:
To calculate the grams of ammonia produced from hydrogen, stoichiometry is used to convert between grams of reactants and products, and to determine the limiting reactant and theoretical yield. To determine the percent yield, the actual yield is compared to the theoretical yield using a specific formula.
Explanation:
Understanding Ammonia Production through Chemical Reactions
When hydrogen gas (H2) reacts with nitrogen gas (N2) in the presence of an excess of nitrogen, ammonia (NH3) is produced according to the balanced chemical equation: N2 + 3 H2 → 2 NH3. To find out the amount of ammonia produced, we can use stoichiometry which involves mole ratios from the balanced equation to convert from grams of hydrogen to moles of hydrogen, and then to grams of ammonia produced.
For the question regarding the limiting reactant and theoretical yield, we need to compare the mole ratios of nitrogen and hydrogen as given in the balanced chemical equation. The reactant which produces the least amount of product is the limiting reactant, and using this, we can calculate the maximum amount of ammonia that can be formed, known as the theoretical yield.
The calculation of percent yield involves the actual yield of the product obtained from the reaction and the theoretical yield calculated based on stoichiometry. The formula for percent yield is: (Actual Yield / Theoretical Yield) × 100%.
an ecologist who is studying the mineral requirements and daily water intake of a plant species is studying
Final answer:
An ecologist studying plant mineral requirements and water intake is engaging in ecology, a sub-discipline of biology concerned with how organisms interact with their environment and their adaptations for survival.
Explanation:
An ecologist who is studying the mineral requirements and daily water intake of a plant species is focused on the field of biology, particularly the sub-discipline of ecology. This field of study is concerned with the physiological, morphological, and behavioral adaptations that allow organisms to survive in specific habitats. By analyzing these factors, ecologists can predict the needs and sustainability of various species within their ecosystems. For instance, field studies may include collecting data in natural environments on various organisms, while laboratory studies could involve analyzing samples or data gathered in the field or applying mathematical models to predict future outcomes. Ecologists not only conduct research but also work in education, policy advisory, and conservation management, often requiring a broad background in the physical sciences and proficiency in mathematics and statistics.
Final answer:
An ecologist studying a plant's mineral and water needs is engaging in biological research within the field of ecology, at the organism level of ecological study. Their work contributes to various societal needs and typically requires an undergraduate degree in the natural sciences.
Explanation:
Understanding Ecological Study in Biology
An ecologist studying the mineral requirements and daily water intake of a plant species is conducting research that falls within the discipline of biology, particularly within the subdivision of ecology. Ecology is a broad field that examines the relationships between organisms and their environments, including the interactions they have with other species and the non-living parts of their ecosystems. In studying a plant's mineral requirements and water intake, an ecologist engages in research at the organism level, which can contribute vital information for understanding the overall health and functioning of ecological systems.
Ecological research can occur both in natural environments (field studies) and controlled lab settings. Field studies might involve observations and data collection in a plant's natural habitat, whereas laboratory studies could involve controlled experiments to determine the specific mineral and water needs of a plant. Additionally, ecologists use various scientific methods and tools, including computer modeling, to analyze and predict ecological outcomes.
Ecologists contribute to many aspects of human society by managing natural resources, advising on policy, and educating the public. To become an ecologist, one typically pursues an undergraduate degree in a natural science, sometimes followed by specialized training or an advanced degree, acquiring a solid foundation in mathematics and statistics along the way.
What is the best name for the molecule below?
4-ethyl-6-heptene
4-propyl-1-hexene
2-methyl-3-heptyne
3-propyl-5-hexene
How do bacteria in the guts of cows help the cows to digest the grass they eat?
Answer:
A cow's digestive system is quite different from that of humans. Cows eat grass, hay and other plant material that contain hard-to-digest cellulose. To cope with this they have a large stomach with four compartments, with the largest being the rumen.
Explanation:
What is our more modern word for caloric?
What three factors affect the pressure of a gas in a closed container?
The three factors affect the pressure of a gas in a closed container is its temperature, its volume, and the number of its particles.
What are the three factors that affect gases?The number of molecules in the gas is directly proportional to the pressure of the gas. The volume of the gas is inversely proportional to the pressure of the gas. The temperature of the gas is directly proportional to the pressure of the gas.
The three factors that affect gas pressure are the number of gas molecules, the volume of the container and the temperature of the container that includes the gas.
If there are two same-sized containers, and one contains double the amount of gas molecules, this container has a higher gas pressure.
Thus, its temperature, its volume, and the number of its particles are the three factors affect the pressure of a gas in a closed container.
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How many grams of Cl are in 535 g of CaCl₂?
If alcohol is ingested rapidly, the _____ will rise sharply within twenty minutes. blood pressure ABC LD50 BAC
Final answer:
If alcohol is consumed rapidly, the blood alcohol concentration (BAC) will rise sharply within twenty minutes. The rate at which BAC rises is influenced by factors including sex, weight, and genetics, with excessive consumption leading to potential health and safety risks. Legal intoxication often starts at a BAC of 0.08%, and binge drinking can quickly reach this level.
Explanation:
If alcohol is ingested rapidly, the blood alcohol concentration (BAC) will rise sharply within twenty minutes. When alcohol is consumed, it enters the bloodstream and can have immediate effects on the body, depending on the drinker's BAC. Factors like sex, weight, and genetics can affect how quickly BAC rises. It is important to note that the liver metabolizes alcohol at a rate of about 15 mg/dL per hour, so consuming alcohol faster than this rate can lead to rapid increases in BAC. Excessive drinking, as in binge drinking, can elevate BAC to levels that pose serious health and safety risks, including impaired judgment and motor skills, which affect activities such as driving.
Alcohol intoxication is legally defined by specific BAC thresholds, with legal intoxication often beginning at 0.08%. BAC can be measured directly by blood tests or indirectly by breath testing devices like Breathalyzers, which provide an estimation of the ethanol concentration in the breath, indicative of the BAC.
The rise in BAC can have significant consequences, not only legally but also in terms of personal health and safety. Binge drinking, which is the consumption of a large amount of alcohol in a short period, can rapidly increase BAC to 0.08 g/dL. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines binge drinking as reaching this BAC after four drinks for women and five drinks for men within about two hours, emphasizing the dangers associated with such drinking behaviors.
How does the written lewis structure for potassium chloride differ from that of hydrogen chloride?
Final answer:
The Lewis structure of potassium chloride (KCl) shows K+ with no electrons around it and Cl- with eight dots, signifying ionic bonds and full valence shells. In contrast, hydrogen chloride (HCl) has a single line or pair of dots between H and Cl, representing a pair of shared electrons in a covalent bond, with Cl also having three pairs of lone electrons.
Explanation:
The Lewis structures for potassium chloride (KCl) and hydrogen chloride (HCl) differ significantly due to the nature of their bonds. Potassium chloride is an ionic compound consisting of potassium (K+) ions and chloride (Cl−) ions. In its Lewis structure, there are no shared electrons; instead, the potassium atom donates an electron to the chloride atom, resulting in a full outer shell for both ions. The potassium ion is typically represented as a K+ with no dots around it, while the chloride ion is represented as a Cl− with eight dots surrounding it to indicate a full valence shell.
On the other hand, hydrogen chloride is a covalent compound where the hydrogen (H) and the chlorine (Cl) share a pair of electrons, demonstrated in its Lewis structure by a single line (or a pair of dots) between the H and Cl atoms, where each atom contributes one electron to the bond. The chlorine atom also has three pairs of lone electrons that are not involved in the bond, represented by three additional pairs of dots around the Cl atom.
Due to these differences in bonding, the ionic forces in KCl lead to a crystalline solid structure at room temperature, while HCl, which consists of discrete covalent molecules, forms a gaseous compound under similar conditions.
"Which piece of evidence would suggest an unknown substance is an ionic compound?
"
It conducts electricity when dissolved in water.
It is a liquid at room temperature.
It is a gas at room temperature.
It has a low melting point.
Which contains more molecules of water, 4.55 cm3 of ice (0.917 g/cm3 ) at 0◦C or 4.55 cm3 of liquid water at 0◦C? 1. the ice 2. the liquid?
How many more molecules?
Answer in units of molec.
I know its the liquad water but how do I find how many more molecules there are
I did:
m/v=d for ice and liquad water
ice mass= 0.917*5= 4.585
liquad water mass= .9998*5= 4.995
then subtracted 4.995-4.585= .41 and converted g to mol= .02277*6.022x10^23= 1.3716E22 but its wrong!!
Answer:
answer was A on edunity
Explanation:
A reaction produces 0.883 moles of H₂O. How many molecules are produced?
Consider the balanced equation below.
8H2 + S8 ---> 8H2S
Based on the mole ratios, what can most likely be predicted?
1 mol of hydrogen will react with 1 mol of sulfur.
8 mol of hydrogen will react with 1 mol of sulfur.
8 mol of hydrogen will react with 8 mol of sulfur.
16 mol of hydrogen will react with 8 mol of sulfur.
Answer : The correct option is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
Explanation :
The balanced chemical equation is,
[tex]8H_2+S_8\rightarrow 8H_2S[/tex]
By the stoichiometry we conclude that, 8 moles of hydrogen react with 1 mole of sulfur to give 8 moles of hydrogen sulfide.
Hence, the correct options is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
Why are valence electrons important?
Valence electrons are important because they are the outermost electrons in an atom and are responsible for the chemical characteristics of an element.
Electrons are the negatively charged particles and are present in the orbitals of an atom.
These electrons participate in chemical reactions and produce compounds by joining with other atoms.
Reactivity of an element is determined by the number of valence electrons and the types of chemical bonds it can form.
The electrical conductivity of materials is also determined by the presence of valence electrons.
Therefore, valence electrons control an element's chemical characteristics, define its reactivity and bonding, and influence the electrical conductivity of materials, they are crucial.
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hy did dr. tyson decide to exclude pluto from the exhibits of planets
What volume of 0.140 HCl is needed to neutralize 2.58 of Mg(OH)2
? ...?
Final answer:
The volume of HCl needed to neutralize a given amount of Mg(OH)₂ can be found by first writing the balanced chemical equation, determining the moles of Mg(OH)₂, calculating the moles of HCl required, and then using the molarity of the HCl solution to find the necessary volume.
Explanation:
To calculate the volume of HCl needed to neutralize a certain amount of Mg(OH)₂, we first need to write the balanced chemical equation for the reaction:
Mg(OH)₂ + 2 HCl -> MgCl₂ + 2 H₂O
From the equation, we see that it takes 2 moles of HCl to neutralize 1 mole of Mg(OH)₂. Say we calculate the moles of Mg(OH)₂ using its molar mass, then we can determine the moles of HCl required. After that, using the molarity of the HCl solution, we can find the volume of HCl needed.
For example, assuming we have x moles of Mg(OH)₂:
Moles of HCl required = 2x moles
Volume of HCl = Moles of HCl / Molarity of HCl solution
The volume calculated will give us the answer to how much HCl is required to neutralize the Mg(OH)₂.
What is a mutual attraction between the nuclei and electrons in two different atoms called?
A) a chemical bond
B) a compound
C) a cation
D) a anion
The answer is A. chemical bond
Answer: The correct option is A
Explanation:
Chemical bond is a bond present when there is mutual attraction between the nuclei and valence electrons of two different atoms to bind the atoms together. A compound is a formed when two different elements combine together in a fixed ratio.A cation is a positively charged ion.An anion is a negatively charged ion.Therefore, the correct option is A.
Why do you think the transition metals are 10 columns wide?
The transition metals are 10 columns wide on the periodic table because each d subshell can hold up to 10 electrons. This configuration leads to a variety of properties, as shown by the diverse reactivity and color of compounds among transition metals.
Explanation:
The transition metals are 10 columns wide on the periodic table due to the configuration of their electrons, specifically in their d orbitals. Each d subshell can accommodate up to 10 electrons, structured as 5 sets of paired electrons. This is connected to the arrangement of the transition metals in the periodic table, which are organized based on electron configuration.
The transition metals, as partially filled d orbitals, are located in the d-block of the periodic table. They vary widely in terms of reactivity, with some being very active metals like scandium and iron, while others being almost inert, such as the platinum metals.
The transition metals exhibit a variety of properties due to their complex valence shells. Because these elements have several different stable oxidation states, electron transitions in these elements can correspond with absorption of photons in the visible spectrum, causing a variety of colored compounds.
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What is the approximate tangential speed of an object orbiting Earth with a radius of 1.8 × 108 m and a period of 2.2 × 104 s?
7.7 × 10^–4 m/s
5.1 × 10^4 m/s
7.7 × 10^4 m/s
5.1 × 10^5 m/s
Answer:
5.1 × 10^4 m/s
Explanation:
Final answer:
The approximate tangential speed of the object orbiting Earth is 7.7 × 10⁴ m/s.
Explanation:
To find the approximate tangential speed of an object orbiting Earth, we can use the formula v = 2πr/T, where v is the tangential speed, r is the radius of the orbit, and T is the period of the orbit.
Given that the radius of the orbit is 1.8 × 10^8 m and the period is 2.2 × 10⁴ s, we can substitute these values into the formula:
v = (2π)(1.8 × 10⁸ m)/(2.2 × 10⁴ s) = 7.7 × 10⁴ m/s
Therefore, the approximate tangential speed of the object orbiting Earth is 7.7 × 10⁴ m/s.
There are 342 g of sucrose in 1.00 mol of sucrose. What is the molar concentration (molarity) of a solution containing 171 g sucrose in 1.25L solution?
A confirmation drug test is for the purpose of identifying specific drugs and the amounts present in the blood system. True False
What is 0.000000639 in scientific notation
Hello!
Order of magnitude of a measure is an estimate of the base power 10 closest to a given measure.
The scientific notation (N) of 0.000000639 (x), being (number of decimal places) y, knowing that the scientific notation according to the rule of scientific notation, before the comma can only have the numbers 1 to 9, let's see:
[tex] N = x*10^y [/tex]
[tex] N = 0.000000639*10^y [/tex]
[tex] \boxed{\boxed{N = 6.39*10^{-7}}}\end{array}}\qquad\checkmark [/tex]
note: Moved 7 decimal places to the right negatively
I Hope this helps, greetings ... DexteR! =)
What allows composites (such as carbon-fiber-reinforced polymers) to be so strong and elastic? Select all that apply.
- high kinetic energy of the molecules
- extensive cross-linking between molecules
- size of polymer molecule
- properties of metals and plastics
Two of the below answers are correct.
extensive cross-linking between molecules properties of metals and plasticsExplanation:A composite material also known as composition material or shortened to composite, is a material made up of two or more component materials with significantly different physical or chemical properties. when combined, provide a material with properties different from the individual.
so the properties that make carbon fiber strong and elastic are extensive cross linkage between molecules, And they also contain both properties of liquid and solid.
is AgOH aqueous or a solid?
Answer : AgOH is a solid.
Explanation;
AgOH can be produced from the reaction between NaOH(aq) and AgNO₃(aq). The balanced reaction equation is
NaOH(aq) + AgNO₃(aq) AgOH(s) + NaNO₃(aq)
AgOH is a brown color precipitate which has a Ksp value as 6.8 x 10⁻⁹. The molecular weight of AgOH is 124.88 g/mol.
Silver Hydroxide (AgOH) is generally a solid at room temperature, but its state can change under different conditions. It is not typically found in aqueous form.
Explanation:In the field of Chemistry, AgOH, also known as Silver Hydroxide, is considered to be a solid at room temperature. Silver Hydroxide is an unstable compound that decomposes easily into its constituent water and silver oxide. Hence, it is not typically found in aqueous (dissolved in water) form. However, it's important to understand that its state can change under different conditions such as temperature and pressure.
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Binary ionic compounds are named in what pattern?
A. The metal followed by nonmetal.
B. The nonmetal followed by the metal.
C. The metal followed by the polyatomic ion.
D. The anion followed by the cation.
For a hydrogen-like atom, classify these electron transitions by whether they result in the absorption or emission of light: n=3 to n=5, n=1 to n=3, n=3 to n=2, n=2 to n=1? Ignoring the sign, which transition was associated with the greatest energy change?