Answer:
IT IS A CHEMICAL CHANGE
Explanation:
The Old Nassau reaction or Halloween reaction is a chemical clock reaction in which a clear solution turns orange and then black
Answer:
It's a chemical change.
A human hair is 75 um across. How many inches is this?
Answer:
2.9528e-6
Explanation:
or 0.0029
Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.
Answer:
474 nm or 4.74 x 10^2 nm
Explanation:
c = λv
c (speed of light) = 2.998 x 10^8 m/s
λ = ?
v = 6.32 × 1014 Hz = 6.32 × 1014 1/s
2.998 x 10^8 m/s = (λ)(6.32 × 10^14 1/s)
λ = (2.998 x 10^8 m/s) / (6.32 × 10^14 1/s)
λ = 4.74 x 10^-7 m
λ = 4.74 x 10^-7 m x (1 x 10^9 nm/1 m) = 474 nm
Calculate the number of miles of magnesium,chlorine, and oxygen atoms in 5.00 moles of magnesium perchlorate
Answer:
5.00 mol Mg
10.0 mol Cl
40.0 mol O
Explanation:
Step 1: Given data
Moles of Mg(ClO₄)₂: 5.00 mol
Step 2: Calculate the number of moles of Mg
The molar ratio of Mg(ClO₄)₂ to Mg is 1:1.
5.00 mol Mg(ClO₄)₂ × 1 mol Mg/1 mol Mg(ClO₄)₂ = 5.00 mol Mg
Step 3: Calculate the number of moles of Cl
The molar ratio of Mg(ClO₄)₂ to Cl is 1:2.
5.00 mol Mg(ClO₄)₂ × 2 mol Cl/1 mol Mg(ClO₄)₂ = 10.0 mol Cl
Step 4: Calculate the number of moles of O
The molar ratio of Mg(ClO₄)₂ to Cl is 1:8.
5.00 mol Mg(ClO₄)₂ × 8 mol O/1 mol Mg(ClO₄)₂ = 40.0 mol O
someone help with this will mark brainliest
Answer:
The main difference between emission and absorption spectra is that an emission spectrum has different coloured lines in the spectrum, whereas an absorption spectrum has dark-coloured lines in the spectrum.l
can be used to help an individual with an eating disorder learn better ways to cope with stress an
replace unhealthy behaviors with those that do not cause harm.
A. Preventative care
B. Hospitalization
C. Medication
D. Psychotherapy
Answer: Psychotherapy
Explanation:
Edge
Answer:
D. Psychotherapy
Explanation:
Did the test
periodic table for the first twenty elements
Answer:
periodic table for the first twenty elements
Answer:
Explanation:
hope this helps
1. During an endothermic chemical reaction, a gas is consumed and a liquid produced.
a. Yes.
b. No.
c. Can't decide with information given.
2. A gas condenses to a liquid, neither absorbing nor releasing heat.
a. Yes.
b. No.
c. Can't decide with information given.
Which of the following environments are low-level areas that can be temporarily or seasonally filled with water?
Rainforest
Swamp
Tundra
Wetland giving brainlist HAS TO BE RIGHT
Answer:
Rainforest
Explanation:
Swamps are permanently filled with water
and Tundras are dry and cold so the answer should be Rainforest
Answer:
its rainforest it's a it's
Explanation:
Question 1
Describe a procedure you could follow to determine the specific heat of a 45-g piece of metal.
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
Explain why the upper phase, after reflux, contained the 1-bromopentane, even though its expected density is 1.276 g/cm3, and the density of water is ~1.00 g/cm3. Think what is in the aqueous solution (e.g., what is the density of salt water
Answer:
The water is not pure i.e. It contains some hydroxide and bromobutane ions that is why the upper phase contains 1-bromopentane
Explanation:
The upper phase after reflux will contain 1-bromopentane even when its density is 1.276g/cm^3 because even though the density of water = 1.00g?cm^3 the water is not pure i.e. It contains some hydroxide and bromobutane ions making it to stay at the bottom while 1- bromobutane stays at the upper phase
first American president
A sample of copper has a density of 10.50g/cm3 and measures of 0.400 dm long,20.0 mm high and 0.003 m thick. What is the mass in grams of this block of copper metal?
QUESTION TWO
2.1
Discuss the process of the scientific method and clarify what is meant
by the science process skills.
(5)
Answer: The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observation.
Explanation:
Hope this helps. :)
calculate the amount of heat energy required to heat up 23.2 grams of ice from -21° C to 56° C ** please show your work**
The second option 1,870.4 Joules
The sky on Earth is blue because blue light is scattered through the atmosphere as the other colors of light pass
through undisturbed. Which nebulae have something similar happening?
Emission nebulae
Dark nebulae
Reflection nebulae
Planetary nebulae
Answer:
C
Explanation:
How many hydrogen atoms are present in H2SO4+H2O?
A blend or combination of genetic material of the parents.
Question 2
What do variations of inherited traits between parent and offspring arise from?
Answer:
Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited.
Explanation:
which of the following human activities are not related to an increase in global temperature
How many moles of Hydrogen fluoride are formed from 10 moles of fluorine?
200.063
Hope this helps :T
Plz help me plz I am timed!!
Answer:
full moon
Explanation:
....ur welcome..............
Answer:
full moon
Explanation:
4) Which of the following can cause erosion?
- Glaciers, wind, and animals
- Acid rain, animals, and ice wedging
- Wind, water, glaciers
- Glaciers, wind, and acid rain
5) Which factors affect the rate of weathering?
- Temperature, ocean currents, and tides
- Type of rock and amount of precipitation
- Type of plants and animals
- Amount of sunlight
Water, air, and even ice are fluids because they tend to flow from one place to another due to the force of gravity.
Rainfall and temperature can affect the rate in which rocks weather. High temperatures and greater rainfall increase the rate of chemical weathering. 2. Rocks in tropical regions exposed to abundant rainfall and hot temperatures weather much faster than similar rocks residing in cold, dry regions.
At 2000 ∘C the equilibrium constant for the reaction 2NO(g)⇌N2(g)+O2(g) is Kc=2.4×103. If the initial concentration of NO is 0.175 M , what is the equilibrium concentration of N2?
Answer:
[tex][N_2]=0.0866M[/tex]
Explanation:
Hello there!
In this case, in agreement to the chemical reaction, it is possible for us to figure out the equilibrium concentration of the N2 product, via an ICE table plugged in the equilibrium expression:
[tex]Kc=\frac{[N_2][O_2]}{[NO]^2}\\\\2.4x10^3=\frac{x*x}{(0.175-2x)^2}[/tex]
In such a way, when solving for x via quadratic equation or just a solver, it is possible to obtain:
[tex]x_1=0.0866M\\\\x_2=0.0884M[/tex]
In such a way, since the root 0.0884 M produce a negative concentration of NO (0.175-2*0.0884=-0.0018M), we infer that the correct root is 0.0866 M; therefore, the concentration of N2 at equilibrium is equal to x:
[tex][N_2]=x=0.0866M[/tex]
Best regards!
:^
Calculate the mass of a sample of CaCl2 containing 2 mol of this substance
Answer:
221.96 g
Explanation:
Step 1: Given data
Moles of calcium chloride (n): 2 mol
Step 2: Calculate the molar mass of calcium chloride
The molar mass of the compound is equal to the sum of the molar masses of the elements that form it.
M = 1 × M(Ca) + 2 × M(Cl)
M = 1 × 40.08 g/mol + 2 × 35.45 g/mol = 110.98 g/mol
Step 3: Calculate the mass (m) of calcium chloride
We will use the following expression.
m = n × M
m = 2 mol × 110.98 g/mol = 221.96 g
Acid formulas usually start with ______________ because they have hydrogen atoms combined with other atoms in their molecules
Answer:
H
Explanation:
Example,
HCl for hydrochloric acid
H2SO4 for sulphuric acid
HNO3 for nitric (v) acid
Calculate the number of nickel atoms in a 5-cent coin of mass 0.942g if it was made of an alloy consisting of 75% copper and 25% nickel.
Answer:
2.41x10²¹ atoms
Explanation:
First we calculate the mass of nickel in the coin, using the given mass and percent composition:
0.942 g * 25/100 = 0.2355 g NiThen we convert 0.2355 grams of nickel to moles, using its molar mass:
0.2355 g Ni ÷ 58.69 g/mol = 0.004 molFinally we convert moles into number of atoms, using Avogadro's number:
0.004 mol * 6.023x10²³ atoms/mol = 2.41x10²¹ atomsThe compound borazine consists of 40.29% boron, 7.51%
hydrogen, and 52.20% nitrogen, and its molar mass is
80.50 g/mol. Calculate the molecular formula for borazine.
Answer:
[tex]B_3H_6N_3[/tex]
Explanation:
Hello there!
In this case, since the mass percentages in a compound which is wanted to know the molecular formula, can be assumed to be the masses, we first need to compute the moles they have in the formula unit:
[tex]n_B=40.29gB*\frac{1molB}{10.811gB} =3.73molB\\\\n_H=7.51gH*\frac{1molH}{1.01gH} =7.44molH\\\\n_N=52.20gN*\frac{1molN}{14.01gN} =3.73molN[/tex]
Next, we divide each moles by the fewest ones (3.73 mol) in order to find the subscript in the empirical formula first:
[tex]B:\frac{3.73}{3.73}=1 \\\\H:\frac{7.44}{3.73}=2\\\\N:\frac{3.73}{3.73}=1[/tex]
Then, the empirical formula is BH2N whose molar mass is 26.83 g/mol, so the ratio of molecular to empirical is 80.50/26.83=3; therefore, the molecular formula is three times the empirical one:
[tex]B_3H_6N_3[/tex]
Best regards!
In an ocean wave, what happens to a water molecule after it transfers its kinetic energy to another water molecule?
In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels. ... In water waves, energy is transferred through the vibration of the water particles.
6621.5 kJ of heat is required to convert a 20.5 g sample of
aluminum from the solid to liquid phase. What is the heat of
fusion of aluminum in kJ/g?
kJ/g
Answer:
323 kJ/g
Explanation:
ck-12 said it was correct
If 1.3 moles of silicon dioxide react with 2.5 moles of carbon, how many grams of carbon
monoxide form?
Answer:
46.76 g
Explanation:
The reaction that takes place is:
SiO₂ + 3C → SiC + 2COFirst we determine the limiting reactant:
1.3 moles of SiO₂ would react completely with (3 * 1.3) 3.9 moles of C. There are not as many C moles, meaning that C is the limiting reactant.
Now we convert C moles (the limiting reactant) into CO moles, using the stoichiometric coefficients:
2.5 mol C * [tex]\frac{2molCO}{3molC}[/tex] = 1.67 mol COFinally we convert 1.67 moles of CO to grams, using its molar mass:
1.67 mol CO * 28 g/mol = 46.76 g