A Gold ring is a what?
Element
Compound
Colloid
Alloy
Answer: Alloy
Explanation: gold is an alloy, or mixture of metals
A sample of hydrate sodium carbonate has a mass of 71.5 g. after heating, the anhydrous sodium carbonate has a mass of 26.5 grams. Calculate the % water.
Answer:
62.9%
Explanation:
Step 1: Given data
Mass of hydrate sodium carbonate (mNa₂CO₃.xH₂O): 71.5 gMass of anhydrous sodium carbonate (mNa₂CO₃): 26.5 gStep 2: Calculate the mass lost of water
We will use the following expression.
mH₂O = mNa₂CO₃.xH₂O - mNa₂CO₃
mH₂O = 71.5 g - 26.5 g = 45.0 g
Step 3: Calculate the percent of water in the hydrate sodium carbonate
We will use the following expression.
%H₂O = mH₂O / mNa₂CO₃.xH₂O × 100%
%H₂O = 45.0 g / 71.5 g × 100%
%H₂O = 62.9%
Balance the following chemical equation: N2H4+O2→ NO2+H2O
Answer:
N2H4 + 3O2 → 2NO2 + 2H2O
Explanation:
675 g of carbon tetrabromide is equivalent to how many
mol. Make sure to round your answer to the nearest WHOLE NUMBER
2.04 mol CBr₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Organic
Writing Organic CompoundsWriting Covalent CompoundsOrganic PrefixesAtomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
675 g CBr₄
Step 2: Identify Conversions
Molar Mass of C - 12.01 g/mol
Molar Mass of Br - 79.90 g/mol
Molar Mass of CBr₄ - 12.01 + 4(79.90) = 331.61 g/mol
Step 3: Convert
[tex]\displaystyle 675 \ g \ CBr_4(\frac{1 \ mol \ CBr_4}{331.61 \ g \ CBr_4}) = 2.03552 \ mol \ CBr_4[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.03552 mol CBr₄ ≈ 2.04 mol CBr₄
Answer:
[tex]\boxed {\boxed {\sf About \ 2.04 \ moles \ of \ CBr_4}}[/tex]
Explanation:
1. Define Formula
The compound is carbon tetrabromide. The tetra indicates 4 atoms of bromine.
Carbon (C)+ 4 Bromine (Br) = CBr₄2. Find Molar Mass
There are 2 elements in this compound: carbon and bromine. Use the Periodic Table to find the molar masses of these elements.
Carbon (C): 12.011 g/mol Bromine (Br): 79.90 g/molThe molar mass is based on the number of atoms in the compound. The compound has 1 atom of carbon and 4 atoms of bromine.
CBr₄= 1(12.011 g/mol) + 4(79.90 g/mol)
= 12.011 g/mol+319.60 g/mol = 331.611 g/mol
3. Convert Grams to Moles
We want to convert 675 grams to moles. We should use the molar mass as a fraction.
[tex]\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]
Multiply by the given number of grams.
[tex]675 \ g \ CBr_4 *\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]
Flip the fraction so the grams of CBr₄ will cancel.
[tex]675 \ g \ CBr_4 *\frac{1 \ mol \ CBr_4 }{331.611 \ g \ CBr_4}[/tex]= [tex]675 \ *\frac{1 \ mol \ CBr_4 }{331.611 \ }[/tex]
[tex]\frac{675 \ mol \ CBr_4 }{331.611 \ }[/tex] = [tex]2.03551752 \ mol \ CBr_4[/tex]
4.Round
The original measurement, 675 grams has 3 significant figures (6,7 and 5), so our answer must have the same.
For the answer we found, 3 sig figs is the hundredth place.
[tex]2.03551752 \ mol \ CBr_4[/tex]
The 5 in the thousandth place tells us to round the 3 to a 4.
[tex]\approx 2.04 \ mol \ CBr_4[/tex]
There are about 2.04 moles of carbon tetrabromide in 675 grams.
Suppose that you take a sample of 500 g of ocean water and let the water evaporate. The mass of the remaining salts is 17 g. What was the salinity of the ocean water
Answer: The salinity of ocean water is 34 ppt.
Explanation:
Salinity is defined as the number of grams of salts present per kilogram of seawater. It is expressed in parts per thousand.
The formula used to calculate the salinity of ocean water or sea water is:
[tex]\text{ Parts per thousand}=\frac{\text{Mass of salts}}{\text{Mass of sea water}}\times 1000[/tex]
We are given:
Mass of salts = 17 g
Mass of sea water = 500 g
Putting values in above equation, we get:
[tex]\text{ Parts per thousand}=\frac{17g}{500g}\times 1000\\\\\text{ Parts per thousand}=34[/tex]
Hence, the salinity of ocean water is 34 ppt.
Which statement describes how upwelling occurs?
O A. Saltier water sinks as water above it freezes and forms sea ice.
O B. Saltier water rises as denser freshwater sinks. .
O C. Denser water rises as less dense water sinks. .
D. Denser water rises to replace surface water pushed by wind.
Answer:
Upwelling occurs when winds push surface water away from the shore and deeper water rises to fill the gap. During upwelling, wind-displaced surface waters are replaced by cold, nutrient-rich water that wells up from below.
Explanation:
So Really its D
A certain ore is 37.3 % nickel by mass. How many kilograms of this ore would you need to dig up to have 65.0 g of nickel
Answer:
0.174kg of Ore are required
Explanation:
The ore of 37.3% in nickel by mass means that in 100g of ore there are 37.3g of nickel. As we need to obtain 65g of nickel we can convert this mass to mass of ore using the conversion factor (100g Ore / 37.3g Nickel) as follows:
65g of nickel * (100g Ore / 37.3g Nickel) = 174g of Ore are needed to have 65.0g of nickel. In kilograms:
174g Ore * (1kg / 1000g) =
0.174kg of Ore are requiredFe(NO3)3 is dissolved in enough water to make exactly 323 ml of solution, what is the molar concentration g
Answer:
0.0659M
Explanation:
...5,15g of Fe(NO₃)₃ is dissolved...
Molar concentration is the amount of moles presents in 1L of solution. To solve this question we need to find the moles of iron nitrate, Fe(NO₃)₃ present in the 323mL of solution:
Moles Fe(NO₃)₃ -Molar mass 241.86g/mol-:
5.15g Fe(NO₃)₃ * (1mol / 241.86g) = 0.0213moles Fe(NO₃)₃
And molarity is:
0.0213moles Fe(NO₃)₃ / 0.323L = 0.0659M
What does a control group show in an experimental investigation?
Answer:
the effects that the scientists are causing by manipulating varuables
if x-2 is a factor of x^m - 3x^m-1 +4x-4,find the value of m.
Explanation:
By Factor Theorem,
(2)^m - 3(2)^(m-1) + 4(2) - 4 = 0.
=> 2^m - 1.5 * 2^m + 4 = 0
=> 4 - 0.5 * 2^m = 0
=> 0.5 * 2^m = 4
=> 2^m = 8
=> m = 3.
Hence the value of m is 3.
48 g of Aluminum will produce how much heat (in kJ) for this reaction?
Use the following reaction:
2 Al + 3 CuSO4 → 3 Cu + Al2(SO4)3 ∆H = -680 kJ
Round your answer to a positive whole number and do not write the unit.
The heat produced from 48 g Aluminium = -578
Further explanationGiven
Reaction
2 Al + 3 CuSO4 → 3 Cu + Al2(SO4)3 ∆H = -680 kJ
48 g of Aluminum
Required
Heat released
Solution
mol of Aluminium = mass : Ar Al
mol = 48 g : 27 g/mol
mol = 1.78
From the reaction, heat released for 2 moles Al, so for 1.78 Al, the heat released :
[tex]\tt \dfrac{1.7}{2}\times -680~kJ=-578~kJ[/tex]
if 3.26 g of FeNO33 is dissolved in enough water to make exactly what is the molar concentration of nitrate ion g
Answer:
0.404M
Explanation:
...To make exactly 100.0mL of solution...
Molar concentration is defined as the amount of moles of a solute (In this case, nitrate ion, NO₃⁻) in 1 L of solution.
To solve this question we need to convert the mass of Fe(NO₃)₃ to moles. As 1 mole of Fe(NO₃)₃ contains 3 moles of nitrate ion we can find moles of nitrate ion in 100.0mL of solution, and we can solve the amount of moles per liter:
Moles Fe(NO₃)₃ -Molar mass: 241.86g/mol-:
3.26g * (1mol / 241.86g) =
0.01348 moles Fe(NO₃)₃ * (3 moles of NO₃⁻ / 1mole Fe(NO₃)₃) =
0.0404 moles of NO₃⁻
In 100mL = 0.1L, the molar concentration is:
0.0404 moles of NO₃⁻ / 0.100L =
0.404MWhat is the initial temperature under the beaker?
The initial temperature of water in the beaker is 20⁰C .
What one word completes the
If a plant is losing water faster than it can be replaced by its roots, its stomata will
sentence?
Answer:
it causes the cells to become flaccid and the stomata openings to close
Explanation:
the stomata closes to reduce water loss
When a plant is losing water at a greater rate than it can be replaced by its roots, then in such a case, the stomata will get close to reduce the loss of water.
• Generally, the opening of stomata takes place in the day and gets close at night. To prevent the loss of water stomata get close during the night.
• However, in certain cases, even during the day, when the plant experiences loss of water due to conditions like drought then stomata remain close during the day also.
• This opening and closing of stomata take place as a response to the signals from the external environment.
Therefore, when more amount of water is loosing from the plant than getting absorbed by the roots, the stomata gets the signal to remain close to prevent water loss and death of the plant.
To know more about stomata and water loss:
https://brainly.com/question/2611673
please help..............
Answer:
hope this help
Explanation:
change: volume of solid , volume of liquid , the volume of gases
not change: the shape of solid , the shape of liquid , the shape of gases
Predict the reactants of this chemical reaction. That is, fill in the left side of the chemical equation. Be sure the equation you submit is balanced. (You can edit both sides of the equation to balance it, if you need to.) Note: you are writing the molecular, and not the net ionic equation.
Answer:
Hydrogen chloride (HCl) and Calcium hydroxide (CaOH). (see balanced equation below)
Explanation:
In a neutralization reaction as is the case of the question (see attachment), an acid would be neutralized by a base to form salt and water.
The most plausible reactants for the reaction given the number of moles of the product, is therefore Hydrogen chloride (HCl) and Calcium hydroxide (Ca(OH)2).
[tex]HCl _{(aq)} + Ca(OH)_{2} _{(aq)}[/tex] →[tex]CaCl_{2}_{(s)} + H_{2} O_{(l)}[/tex]
Let me know if this was helpful.
How many protons, neutrons, and electrons does sulfur have
Answer:
Name
Sulfur
Atomic Mass
32.066 atomic mass units
Number of Protons
16
Number of Neutrons
16
Number of Electrons
16
Explanation:
Answer:
Explanation:
16 protons
16 electrons
16 neutrons
which animal takes on the temperature of their surroundings and does not use food energy to keep warm
Using the diagram above, answer the following questions:
6. True or False. The arrow labeled C represents a transfer of chemical energy to mechanical energy. Explain why this is true or false. –
7. True or False. The arrow labeled A represents a transfer of solar energy to chemical energy. Explain why this is true or false. –
8. Which arrow or arrows represent a release of carbon dioxide? What process is occurring at the arrow(s) you selected?
9. Which arrow or arrows indicate a process that cycles carbon from living or nonliving organisms? Describe the process or processes you selected.
10. Which arrow or arrows represent reactions that demonstrate a conservation of mass and energy? Explain your answer.
PLEASE HELP!
Answer:
6. false.
chemical energy to heat and mechanical. Mechanical that runs the factory in the photo, and Heat energy that rises up in the atmosphere to join the other carbon
molecules in the air. 7. True. The arrow letter A is the transfer of solar power
from the sun, to a chemical reaction to produce food for the plant, which is
called photosynthesis. The leaves in the plant has chlorophyll that absorbs light
energy and transforms it to food.8. The answer would be letter C and F. C because It is
during the burning of the fossil fuels that the carbon dioxide is release into
the atmosphere. When burning the fossil fuels the carbon that was inside the
fossils is released. This also happens with diesel and other forms of natural
gas. While, F is because plant
respiration releases some of the carbon remains of the photosynthesis. While
plants do absorb carbon dioxide, part of their end product also includes reformed
carbon dioxide. Most of the other processes in the phot uses carbon or absorbs
carbon dioxide to aid their sustenance.9. A carbon cycle for living things would be A or B to F
wherein the plants absorb carbon dioxide to aid their production of food, and
then releasing carbon dioxide again as a by product of their food production.
This also happen to aquatic plants.An example of a non-living carbon cycle would be, D or E to
C. This would be the absorption of the carbon on our sea waters or to our soil,
this then gets trapped in there until it is release like through the forms of
fossil fuel burning.10. The law of conservation of mass and energy states that
matter can neither be created nor destroyed, this is very much evident in the
carbon cycle. Because the carbon from the light energy from the sun, or in our
atmosphere, ends up back to our atmosphere just to continue its cycle. The fact
that the carbon cycle is a cycle not just a linear equation proves that energy
can neither be created nor destroyed.
Explanation:
Which correctly lists three characteristics that are used to describe air?
O Altitude, density, radiation
O Density, radiation, mass
O mass, pressure, density
O pressure, altitude, radiation
Answer:
Mass Pressure and density.
Explanation:
The density of a pure substance is its mass per unit volume. The density of ethylene glycol has been measured to be 1097.gL. Calculate the mass of 405.mL of ethylene glycol. Be sure your answer has a unit symbol and the correct number of significant digits.
Answer: The mass of 405 mL of ethylene glycol is 444.3 g.
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Given :
Density of the ethylene glycol= [tex]1097g/L[/tex]
Volume of the ethylene glycol= [tex]405ml[/tex] = 0.405 L (1L=1000ml)
Mass of the ethylene glycol = ?
Putting in the values we get:
[tex]1097g/L=\frac{x}{0.405L}[/tex]
[tex]x=444.3g[/tex]
Thus the mass of 405 mL of ethylene glycol is 444.3 g
What is the difference between an atomic symbol and a chemical symbol?
Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
What is the value of 4a? when a= 3?
Answer:
12
Explanation:
4x3 is 12
Answer:
To solve this simple expression you must substitute [tex]a[/tex] for the number you are given, so, 3.
4[tex]a[/tex] -> 4 3
Now, when numbers are next to each other like this, they are always multiplied. So, the find the answer you would multiply 4 times 3...
4 x 3 = 12
So, you answer will be 12!
The atomic number tells the number of
A solution is made by mixing 49.g of chloroform CHCl3 and 73.g of acetyl bromide CH3COBr. Calculate the mole fraction of chloroform in this solution. Round your answer to 2 significant digits.
Answer: The mole fraction of chloroform in this solution is 0.41
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
a) moles of [tex]CHCl_3[/tex]
[tex]\text{Number of moles}=\frac{49g}{119g/mol}=0.41moles[/tex]
b) moles of [tex]CH_3COBr[/tex]
[tex]\text{Number of moles}=\frac{73g}{123g/mol}=0.59moles[/tex]
To calculate the mole fraction, we use the formula:
[tex]\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}[/tex]
[tex]\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41[/tex]
The mole fraction of chloroform in this solution is 0.41
Explain how the direction of the arrow in the bond dipole symbol ( ) relates to the elec-tron density and the partial charges.
The complete question is shown in the image attached
Answer:
See explanation
Explanation:
In a molecule, the direction of the dipole moment also shows the direction of the shift in electron density. Let me give you an instance. In HCl, the dipole points towards the chlorine atom. This implies that the bond is polar and the chlorine atom accommodates the greater share of the electron density of the H-Cl bond. The negative partial charge rests on the more electronegative atom (chlorine in this case) while the partial positive charge rests on the more electropositive atom(hydrogen in this case). Recall that the difference in electron density between the two atoms creates this polarity.
Having said that much, let me come to the issue of electronegativity and bond polarity. The polarity of bonds depends on the electronegativity difference between atoms. I have just established that the H-Cl bond is polar owing to the difference in electronegativity between hydrogen and chlorine. If I replace the chlorine atom in the molecule with another hydrogen atom, the molecule is no longer polar because the difference in electronegativity of a H-H bond is zero.
Lastly, let me talk about electronegativity difference and bond character. The magnitude of electronegativity difference between atoms determines the bond character. If the electronegativity difference between bonding atoms is;
less than 0.4, the bond is a pure covalent bond
between 0.4 - 1.8, the bond is a polar covalent bond
greater than 1.8, the bond is a pure ionic bond
Group IA elements are very reactive metal . why
Answer:
Alkali metals are among the most reactive metals. This is due in part to their larger atomic radii and low ionization energies. They tend to donate their electrons in reactions and have an oxidation state of +1. ... All these characteristics can be attributed to these elements' large atomic radii and weak metallic bonding.
Explanation:Because they have just one valence electron, group 1 elements are very reactive. As a result, they are found in nature only in combination with other elements. Alkali metals are all solids at room temperature. ... From the top to the bottom of group 1, the elements have heavier, more reactive atoms.
hope it helped :)
What is a hypothesis?
Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
Explanation: definition
Balance the following chemical equation: CH4+ Cl2 → CCl4+ HCI
Answer:
CH4 + 4Cl2 ===> CCl4 + 4HCl
Explanation:
I am pretty sure atleast?
What is a "bond" between atoms?
Answer:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds :)