Answer:For alloys greater than 14 K, aqua regia is used to test the gold. Aqua regia dissolves gold itself (as well as dissolving the silver and copper components) and for this reason it is used to test higher karat gold alloys.
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ITS DUEEE brainliest+15 points place plastic wrap infrony of a flashlight what do you observe? after that place wax paper in front of the flashlight Does the waxed paper affect how the light hits the paper on the wall? Explain your response.
Plastic wrap is transparent and so nearly all light passes through easily ,
Wax Paper is translucent and so light is blurred or scattered .
What is Reflection ?
Reflection of light occurs when light hits a smooth surface that does not absorb any of the light but instead bounces it back off the surface.
A mirror is flat, smooth, and polished. When light hits a mirror it is not absorbed but is reflected off at a very predictable angle.
The angle that the light hits the mirror is called the angle of incidence.
The angle of light that bounces off the mirror is called the angle of reflection.
The Law of Reflection states that the angle of incidence is equal to the angle of reflection.
Plastic wrap is transparent and so nearly all light passes through easily ,
Wax Paper is translucent and so light is blurred or scattered .
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are sedimentary rocks formed weathering erosion and deposition?
Answer:
yes
Explanation:
sedimentary rocks are mad from erosion and weathering!
weathering erosion and deposition occur to form every sedimentary rock that exist on Earth weathering is the creation of sediment through its supposed to wind or water tearing off pieces or do I survive a logical activity such as tree roots and animal hooves breaking at rock erosion is the transportation of the sediments from origin to deposition through wind water or glacial ice deposition is the process of the sediments being dropped off by their mode of movement or erosion method by glacial ice when are water.
Which of the following are examples of useful hydrocarbons?
Answer:
the most useful hydrocarbon is fuel.
Explanation:
some examples like: natural gases,coal,diesel fuel, kerosene etc.
The most useful hydrocarbon is fuel like gasoline, natural gas, fuel oil, diesel, jet fuel, coal, kerosene, and propane.
What are hydrocarbons ?The term hydrocarbon is defined as the compound which is made up of hydrogen and carbon. They are useful as energy sources. Hydrocarbons are examples of group 14 hydrides.
There are four types of hydrocarbon that are alkanes, alkenes, alkynes and aromatic hydrocarbons.
Among the most widely used hydrocarbon fuels include gasoline, natural gas, fuel oil, diesel, jet fuel, coal, kerosene, and propane. Plastics and synthetic fabrics like polyester are made using hydrocarbons as well.
Thus, The most useful hydrocarbon is fuel like gasoline, natural gas, fuel oil, diesel, jet fuel, coal, kerosene, and propane.
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How many mL of 2.52 Macid does it take to titrate 1,527mL of 5.09 M base?
[tex]thanks \: for \: points[/tex]
brainliestmark me as
CARRYONLEARNINGLook at the equation. Which is the Brønsted-Lowry base?
Answer:
the answer is H3O+.......
Answer:
H₂O
Explanation:
A Brønsted-Lowry base accepts protons. As seen in the equation, H₂O gains a proton to become H₃O⁺. It has gained one proton- a hydrogen atom.
C₂H₃O₂⁻ is a conjugate base.
H₃O⁺ is a conjugate acid.
HC₂H₃O₂ is an acid [or a Brønsted-Lowry acid].
A calorimeter holds 50 g water at 22.0°C. A sample of hot iron is added to the water. The final temperature of the water and iron is 28.0°C. What is the change in enthalpy associated with the change in the water’s temperature?
Note: The specific heat of water is 4.18 J/°C
Use the formula ΔH = - cmΔT
The change in enthalpy associated with the change in the water’s temperature is 1254 J.
What is specific heat?The amount of heat required to increase the temperature of one gram of a substance by one Celsius degree is known as specific heat.
Enthalpy change will be calculated as:
ΔH = -cmΔT, where
m = mass of water = 50g
c = specific heat of water = 4.18J/g°C
ΔT = change in temperature = 28 - 22 = 6 °C
On putting values in the above equation, we get
ΔH = -(4.18)(50)(6) = -1254 J
Hence change in enthalpy of the reaction is -1254 J.
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When will the pain end?
Answer:
(when you get a girl)
Pain is a sensory trigger from your brain to represent the fact that something —or someone— could be hurting you. The pain will end once the thing causing it stops, as in a cause-effect scenario.
Mental health though, can be helped by finding happiness in life, like getting off of clash of clans and touching grass.
A sodium chloride solution with a Molarity of 0.239 M has a volume of 158 mL. How many grams
of solute are in the solution?
Answer:
2.21 grams
Explanation:
The first thing you need to do is find the chemical formula for sodium chloride which is NaCl (Molar mass: 58.44 g/mol).
The next the thing to do is to convert the mL to L by dividing by 1000 which will give us 0.158 L.
Now we look at the molarity formula M = n/L, plug in the molarity for M and the liters for L. 0.239 M (mol/L) = n/0.158 L.
Solve for n to get the number of moles of NaCl in the solution. You should get 0.037762 moles.
Then we have to multiply this by the molar mass of NaCl, (0.037762 mol)*(58.44 g/mol).
Moles cancel and when we round to sig figs we are left with 2.21 grams.
Hope this helps.
What is the meteorology tool that is an area where weather data is collected from various sources to make predictions
Answer:
Weather maps im sorry im not sure but i think its the answer
Solve 21 and 22 please
Answer:
try youre best to succsess
Which experiment led to the idea that atoms contained a nucleus?
O A. Niels Bohr's photoelectric effect experiment
O B. Ernest Rutherford's gold foil experiment
O C. J. J. Thomson's cathode ray experiment
O D. Robert Millikan's oil drop experiment
Answer:
B. Ernest Rutherford's gold foil experiment
Explanation:
That experiment showed a space with the tiny dense spot, referred to as the nucleus. The experiment involved shooting alpha particles (helium nuclei) at a very thin sheet of gold and then observing.
Why do scientists use stirbars in the laboratory?
Answer:
A stir bar consists of a magnetic bar used to agitate a liquid mixture or solution
Explanation:
Which statement(s) about neutrons is/are TRUE?
SELECT ALL THAT APPLY
The major clue to their existence was extra mass in
a atoms that protons and electrons could not
account for.
b They were observed and measured directly, like
protons and electrons were.
C They have the same mass as protons.
d They have a negative charge.
Answer:
C
Explanation:
Because D ask "They have a negative charge" yes and no, but neutrons do, Why? Well because the neutron has a negative charge both in its inner core and its outer edge, with a positive charge sandwiched in between to make the particle electrically neutral. Whilst B is wrong because like protons and electrons they were both measured and observed differently, just as the neutron. So that makes C the only correct answer.
2.) At what temperature in Celsius will a 1.0g sample of neon gas exert a pressure of 500 torr in a 5.01 L container. (Hint: use the Ideal Gas Law)
The required temperature of the sample of gas is 823K.
What is ideal gas equation?Ideal gas equation gives idea about the behavior of gas at different condition & represented as:
PV = nRT, where
P = pressure = 500 torr = 0.657 atmV = volume = 5.01 LR = universal gas constant = 0.082 L.atm / K.molT = temperature = ?n = molesMoles will be calculated as:
n = W/M, where
Moles of Neon gas = 1g / 20.1g/mol = 0.049 mole
On putting all these values in the above equation, we get
T = (0.657)(5.01) / (0.049)(0.082) = 822.8 = 823 K
Hence required temperature of the sample is 823 K.
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Hii!
Explain Rutherford's model.
Answer:
Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. This model of an atom was developed by Ernest Rutherford, a New Zealand native working at the University of Manchester in England in the early 1900s
Explanation:
yan na ang exact
Rutherford's atomic model is the model which described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun.
I) Choose The Correct Answer 1. Which of the following statement correctly describes the law of conservation of mass? A/ It states that the total mass of reactants is equals with the total mass of products in all chemical reaction B/ The total numbers of atoms at the left should be equal with the total numbers of atoms at the right side of arrow C/Atom is neither created nor destroyed in any chemical reaction D/ All E/ None
Answer:
D all
Explanation:
because law of conservation of mass describes A, B and C statement
8 marks (a) Given the following information: AH = -116 kJ AH = -256 kJ Eqn. 1: Eqn. 2: 2NO(g) + O2(g) 2NO2(g) 2N2(g) + 502(g) + 2H2O(C) ► 4HNO3(aq) N2(g) + O2(g) → 2NO(g) AH = +183 kJ Eqn. 3: Use Hess's Law to calculate the enthalpy change for the reaction below (Show your working) AHrın = ??? 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g) AHHO
Enthalpy change is the heat that evolved or got absorbed in a reaction mixture. The enthalpy change for the reaction is -137 kJ.
What is Hess's law?Hess's law states that the enthalpy for the whole reaction will be equal to the summation of all changes that are independent of the steps of the reaction.
First, arrange all the reactions and balance them, first the data of equation 1 is rearranged:
NO₂ must be on the reactant side and must be multiplied by 3/2 so that 3 moles of NO are balanced.
3 NO₂ (g) → 3 NO (g) + 3/2 O₂ (g), ΔH = + 174 kJ
Now, for equation 2: the moles of HNO₃ required is 2 so the whole equation will be divided by 2 as,
N₂ (g) + 5/2 O₂ (g) + H₂O (l) → 2HNO₃ (aq), Δ H = -128 kJ
Now, for equation 3: N₂ and O₂ should be eliminated and reversed as,
2NO (g) → N₂(g) + O₂(g) ΔH = -183 kJ
Now, to determine the enthalpy the rearranged equation 1, 2, and 3 are added to get the final equation:
3NO₂ (g) + H₂O (l) → 2HNO₃ (aq) + NO (g)
Δ H = 174 - 128 - 183
= -137 kJ
Therefore, -137 kJ is the enthalpy change.
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___Cu2S (s) + ___O2 (g) → ___Cu (s) + ___SO2 (g)
A. Balance the chemical equation above.
B.hat type of reaction is/are being represented by the chemical reaction in part (a)?
Answer:
(a)Cu2S(s) + O2(g) --> 2Cu(s) + SO2(g)
(b) single displacement reaction
A sample of carbon monoxide gas is contained in a 345 mL vessel at a temperature of 25 °C. and a pressure of 985 mm
Hg. The gas is allowed to expand to a new volume of 4.50 liters at constant temperature. What is the new pressure? 1 atm
= 760 mm Hg.
The new pressure is 75.51 mmHg if a sample of carbon monoxide gas is contained in a 345 mL vessel at a temperature of 25 °C. and a pressure of 985 mmHg and the gas is allowed to expand to a new volume of 4.50 litres at a constant temperature.
What is a gas law?The gas laws consist of three primary laws: Charles' Law, Boyle's Law and Avogadro's Law (all of which will later combine into the General Gas Equation and Ideal Gas Law).
The pressure on the gas changes, while the temperature remains constant, and we want to find the new volume. So, we will use Boyle's Law, which states there is an inverse relationship between the pressure on a gas and the volume of the gas. The formula is:
[tex]P_1V_1=P_2V_2[/tex]
[tex]P_1 = 985 mm Hg[/tex]
[tex]V_1 = 345 mL[/tex] =
[tex]P_2 = ?[/tex]
[tex]V_2 = 4.50 liters[/tex]
The pressure of the gas is originally 985 mm Hg and the volume is 345 mL.
We are solving for the new volume, so we must isolate the variable V₂.
Now putting all the values in the equation:
[tex]P_1V_1=P_2V_2[/tex]
[tex]985 X 0.345 L=P_2 X 4.50[/tex]
[tex]P_2[/tex] = 75.51 mmHg
Hence, the new pressure is 75.51 mmHg.
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What is the equivalent weight of water
Answer:
Atomic weight of Hydrogen is 1. There are 2 Hydrogen atoms in water molecule. So it is 2. Oxygen atomic weight is 16.0 and adding 2 and 16, we will get 18.18 is the equivalent weight of water.
Explanation:
Hope this helps
Which organisms are consumers?
Choose all correct answers.
Mushrooms
Snake
Frog
Grasshopper
Monkey
Grass
Answer:
Snake
Frog
Grasshopper
Monkey
Mushroom
What is pH defined as?
Answer:
pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
Explanation:
hope this helps if not let me know have a great day
2. The figure shows the phase transition of water. Use it to answer question:
C°
120°
5
s/
4
100°
80°
60°
3
40°
20°
2
0°
71
-10°
During which period(s) of time is water in the liquid phase?
A 2
B 2 and 3
C 3
D D 3 and 4
What mass of copper is used to produce 2.87 moles of copper (II) oxide?
The answer is 182 but I don't know why
Answer:
182.532 [gr.].
Explanation:
1) equation of this reaction is:
2Cu+O₂⇒2CuO;
2) according to the equation made up above, ν(CuO)=ν(Cu); it means ν(Cu)=2.87 (mol.), then
3) m(Cu)=ν(Cu)*M(Cu);
m(Cu)=2.87*63.6=182.532 [gr].
(50 points) A chemist reacted 15.0 liters of F2 gas with NaCl in the laboratory to form Cl2 and NaF. Use the ideal gas law equation to determine the mass of NaCl that reacted with F2 at 280. K and 1.50 atm.
F2 + 2NaCl → Cl2 + 2NaF
Part 2. Explain how you would determine the mass of sodium chloride that can react with the same volume of fluorine gas at STP.
A. The mass of NaCl needed to react with F₂ at 280 K and 1.50 atm is 115.83 g
B. The mass of NaCl needed to react with F₂ at STP is 78.39 g
A. How to determine mass of NaCl needed at 280 K and 1.50 atmWe'll begin by calculating the number of mole of F₂ by using the ideal gas equation as follow:
Volume (V) = 15 LTemperature (T) = 280 KPressure (P) = 1.5 atm Gas constant (R) = 0.0821 atm.L/Kmol Number of mole (n) =?n = PV / RT
n = (1.5 × 15) / (0.082 × 280)
n = 0.98 mole
Next, we shall determine the number of mole NaCl that reacts. This is given below
F₂ + 2NaCl → Cl₂ + 2NaF
From the balanced equation above,
1 mole of F₂ reacted with 2 moles of NaCl.
Therefore,
0.98 mole of F₂ will react with = 0.98 × 2 = 1.96 moles of NaCl
Finally, we shall determine mass of NaCl as follow
Mole of NaCl = 1.96 molesMolar mass of NaCl = 58.5 g/mol Mass of NaCl =?Mass = mole × molar mass
Mass of NaCl = 1.98 × 58.5
Mass of NaCl = 115.83 g
B. How to determine mass of NaCl needed at STPAt standard temperature and pressure (STP),
22.4 L = 1 mole of F₂
Therefore,
15 L = 15 / 22.4
15 L = 0.67 mole of F₂
Next, we shall determine the number of mole NaCl that reacts. This is given below
F₂ + 2NaCl → Cl₂ + 2NaF
From the balanced equation above,
1 mole of F₂ reacted with 2 moles of NaCl.
Therefore,
0.67 mole of F₂ will react with = 0.67 × 2 = 1.34 moles of NaCl
Finally, we shall determine mass of NaCl as follow
Mole of NaCl = 1.34 molesMolar mass of NaCl = 58.5 g/mol Mass of NaCl =?Mass = mole × molar mass
Mass of NaCl = 1.34 × 58.5
Mass of NaCl = 78.39 g
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Why does the shape of the moon appear to change over the course of about a month? (2 points)
Group of answer choices
The sun is always lighting up the same amount of the moon.
The sun is lighting up different amounts of the moon.
The moon changes sh
Answer:
The sun is lighting up different amounts of the moon.
Explanation:
Predict the products of each reaction. Balance the equation, and then write the net ionic equation
A chemical equation is an equation showing the formation of new products from reactants.
What is a chemical reaction?A chemical reaction is a reaction which involves changes in the composition and chemical properties of substances resulting in the formation of new substances.
A chemical reaction is usually represented by chemical equations.
A balanced chemical equation is one in which the atoms of elements are equal on both sides of the equation.
A net ionic equation shows only the ions that form products.
Therefore, a chemical equation is an equation showing the formation of new products from reactants.
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How can glass be a liquid if it's so hard?
Answer:
It is an amorphous solid and hence also called pseudo solid. So it flows very slowly over thousands of years. It is not visible to the n*ked eye.
when water becomes tasty it is called?
Answer:
sour ??
Explanation:
PLEASE HELPPPP ASAPPPPPP!!!!!!!
Answer:
that the oxygen atom is not equal on both sides
Explanation:
Thus the reaction is not balanced.