Which of the following is a strong base?
a. h2o
b. NH3
c.CaCo3
d. NaOh
Answer:
d. naoh
Explanation:
3 A 60.00 g sample of tetraethyl lead, a gasoline additive, is found to contain 38.43 g lead, 17.83 g carbon, and 3.74 g hydrogen. Find its empirical formula.
Answer:
The empirical formula is PbC₈H₂₀
Explanation:
To determine the empyrical formula, we need to determine the % of each element:
(38.43g / 60 g ). 100 = 64.05 % of Lead
(17.83 g / 60 g) . 100 = 29.72 % of Carbon
(3.74 g / 60 g) . 100 = 6.23 % of H
Now we divide by the atomic mass:
64.05 / 207.2 = 0.309
29.72 / 12 = 2.48
6.23 / 1 = 6.23
We pick the lowest value and we divide again, with this number
0.309 / 0.309 = 1 Pb
2.48 / 0.309 = 8 C
6.23 / 0.309 = 20 H
PbC₈H₂₀
2. Which of the following is a greenhouse gas?
The element hydrogen contains particles of
OA. water and carbon.
OB. hydrogen only.
OC. hydrogen, oxygen, and nitrogen. OD. oxygen and carbon.
Please HELP!
Answer:
B. hydrogen only.
Explanation:
The element hydrogen is a made up of only hydrogen atoms which are the particles in the element.
Hydrogen is an element. It has distinct hydrogen atoms that typifies it.
Water and carbon is not a hydrogen element. They contain hydrogen, oxygen and carbon.An element is a distinct substance that is made up of one kind of atom. The only kind of atom in element hydrogen is those hydrogen itself.
All energy originates from the _______.
A. biomass
B. mitochondria
C. sun
D. chloroplast
Answer:
sun
Explanation:
because all plants use energy from the sun to make food and grow
........PLEASE HELP........
what are two ways that substances can pass through a cell membrane out of the cell
Answer:
Passive transport, and Active transport
Explanation:
Do u need an explanation?
If so you can tell me and I'll edit it
Hope this helped a little!
solid to liquid change melting
Answer:
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance.
Hope this helps, have a wonderful day/night, stay safe, happy holidays, and merry christmas!
What pieces of evidence do scientists use to support the current theory of rapid expansion?
Answer:
When looking at the radiation emitted by distant stars or galaxies, scientists see emission spectra 'shifted' towards the red end of the electromagnetic spectrum—the observed wavelengths are longer than expected. ... Something causes the wavelength of the radiation (emitted by faraway stars and galaxies)
I am lost someone help me!!
Try tissue
Explanation:
Which set of properties is most characteristic of transition elements?
Answer:
C.
Explanation:
Transition elements like, for example, iron:
Fe2+ green colored in solution.
Fe3+ brown colored in solution.
1. How much heat is required to melt 25.0 g of ice at 0°C?
Answer: The heat required to melt 25.0 g of ice at [tex]0^0C[/tex] is 8350 Joules
Explanation:
Heat of Fusion tells us how much energy is needed to convert 1g of a solid to a liquid at the same temperature.
[tex]Q=m\times L[/tex]
Q = Heat absorbed = ?
m = mass of ice = 25.0 g
L = Latent heat of fusion of ice = 334 J/g
Putting in the values, we get:
[tex]Q=25.0g\times 334J/g=8350J[/tex]
Thus heat required to melt 25.0 g of ice at [tex]0^0C[/tex] is 8350 Joules
What elements does lithium resemble when it loses 1 electron?
Answer:
helium
Explanation:
By losing an electron, they look like the noble gas that immediately precedes them on the periodic table.
Question 12 of 32
The work of which scientist was most essential to the use of the scientific
method and quantitative measurements in chemistry?
A. Antoine-Laurent Lavoisier
B. John Dalton
O C. Robert Boyle
O D. Marie Curie
Answer:
A. Antoine-Laurent Lavoisier
Explanation:
Hope this helped!
Which one is the right answer?
Answer:
a) p waves travel slower then 5 waves
How many neutrons does the isotope have?
Answer:
16 neutrons.
Explanation:
From the question given above, the following data were obtained:
Mass number = 30
Atomic number = 14
Neutron number =?
Next, we shall determine the number of protons present in the isotope. This can be obtained as follow:
The atomic number of an element is simply defined as the number of protons present in the atom of the element. Thus,
Atomic number = Proton number
Atomic number = 14
Therefore,
Proton number = 14
Finally, we shall determine the number of neutons present in the isotope as follow:
Mass number = 30
Proton number = 14
Neutron number =?
Mass number = Proton + Neutron
30 = 14 + Neutron
Collect like terms
Neutron = 30 – 14
Neutron = 16
Therefore, the isotope contains 16 neutrons.
According to the equation for the kinetic energy of a moving object, which gas would have the lowest average velocity, assuming all gases are at the same temperature?
Answer:
O3
Explanation:
According to the equation for the kinetic energy of a moving object, O3 (OZONE) gas would have the lowest average velocity, assuming all gases are at the same temperature.
What is Temperature?A temperature is a unit used to represent hotness or coolness on any of a number of scales, including Fahrenheit and Celsius. According to temperature, heat energy will naturally move from a hotter (body with a higher temperature) to a colder (body with a lower temperature) (one at a lower temperature)
Although these descriptive words are well-known and suitable to describe this landscape, they do not accurately convey temperature. By definition, the temperature is a technique to express warmth and coldness through numerical descriptors. To put it another way, it can provide a subjective description of a comparable, numerical value.
A thermometer is frequently used to measure temperature. The idea of thermal equilibrium must be understood in order to comprehend how thermometers function. Thermal equilibrium occurs when two materials that are in contact are both at the same temperature.
To learn more about Temperature follow the link.
https://brainly.com/question/23411503
#SPJ6
7th grade science , help me please :))
Calculate Ratios In the following reaction, how many molecules of HCI are needed to produce four molecules of H20? 2HCl(aq) + Ca(OH)2(aq) +CaCl2(aq) + 2H20(1)
Answer:
Explanation:
Mole ratios are used as conversion factors between products and reactants in stoichiometry calculations.. For example, in the reaction . 2H₂(g) + O₂(g) → 2H₂O(g) The mole ratio between O₂ and H₂O is #(1 mol O₂)/(2 mol H₂O)#.
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. The mole ratio between HCl and H20 is 1:1.
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
Physical state should be written in brackets. s means solid, l means liquid, g means gas. Mole ratios are used as conversion factors between products and reactants in stoichiometry calculations. The mole ratio between HCl and H20 is 1:1.
Therefore, the correct option is option A.
Learn more about the balanced equation, here:
https://brainly.com/question/7181548
#SPJ2
A 23.7 g piece of iron at 54.9 C is cooled and releases 338 J of heat. The specific heat of iron is 0.450 J/gC. What is the final temperature of the iron?
Answer:
39
Explanation:
cux it is
Answer: 23.3 °C
Explanation: The one above is wrong
Why is an occluded front considered the most complex type of front?
Answer:
folloow mw tiktokjonathan_dion21 for a free cookie
Explanation:
In a covalent compound like O2, two pairs of electrons are shared between the atoms. What is the name given to a bond like this?
Explanation:
The bond is a covalent bond.
what occurs along a convergent plate boundary ?
Answer:
Two plates pull towards each other
Explanation:
Along a convergent plate boundary, two plates moves towards each other as the move in the same direction.
This results in different forms of plate interactions depending on the plate types.
At an ocean - ocean and continental - ocean convergent front, subduction of the oceanic plate occurs. This is because the oceanic plate below is denser than the asthenosphere. At a continental - continental convergent front, the continental crust is pulls upward and build up as a mountain. The subduction produces trenches and some volcanic islands.Answer:
What happens along a convergent plate boundary?
If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. ... The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary
Explanation:
Question 11 of 32
When do scientists form a hypothesis?
A. Before they form a theory
B. After they form a theory
O C. Before they perform an experiment
D. After they perform an experiment
SUBMIT
Answer:
C
Explanation:
a hypothesis always comes first
Answer:
C
Explanation:
They form hypothesis first, then perform the experiment to test the hypothesis. After multiple experiments, they form a theory.
Thus C is correct
please give thanks by hitting that heart button :)
NaH is an iconic compound because
NaH is an ionic compound as shown below, and is made of sodium cations (Na+) and hydride anions (H-). It has the same octahedral crystal structure as NaCl, with each sodium ion surrounded by six hydride ions. The free hydride ions give this molecule its strong basic character. hope this helps
For the hydrolysis of methyl acetate express the rate of reaction in terms of different reactants and products
Answer:
See explanation
Explanation:
The equation of the reaction is;
CH3COOCH3 + H2O -------> CH3COOH + CH3OH
Now recall that the rate of reaction refers to the rate of disappearance of reactants or the rate of appearance of products. We indicate that reactants disappear by a negative sign placed in front of the concentration term of reactants.
Rate = k -d[CH3COOCH3]/dt
Rate = k d[CH3COOH]/dt
Rate = k d[CH3OH]/dt
Note; i did not write the rate in terms of water because it is a solvent that is present in large excess. Its concentration does not change with time.
Define-Ductility, malleability, sonority, electrical conductivity, thermal conductivity
Show, in a step by step fashion, your calculations to determine the percent
by volume of a solution that is made by mixing 50 ml of ethanol with 210
ml of water.
The percent by volume of a solution : 19.23%
Further explanationGiven
50 ml of ethanol
210 ml of water
Required
The percent by volume of a solution
Solution
Percent Volume (% v/v) : volume (ml) of solute/100 ml of solution ⇒ ratio of the volume of the solute to total volume of the solution
[tex]\tt \%solute(v/v)=\dfrac{solute~volume}{solution~volume}\times 100\%[/tex]
solute= Ethanol
solvent=water
Solution = solute+solvent
Total volume of the solution :
[tex]\tt =volume~of~Ethanol+solume~of~water\\\\=50~ml+210~ml\\\\=260~ml[/tex]
Percent by volume :
[tex]\tt \%volume=\dfrac{50}{260}\times 100\%\\\\\%volume=19.23\%[/tex]
Activity
solve the problems below to practice what you have learned. Remember to use the formula for a heat transferred: Q=mC(T: - T:).
Part A
The specific heat of lead is 0.129 yg°C. Find the amount of heat transferred to lead when 355 grams are heated from 95°C to 140°C.
BIŲ x
Font Sizes
Characters used: 15000
Answer:
2060.775 J
Explanation:
From the question given above, we obtained the following data:
Specific heat capacity (C) = 0.129 J/g°C
Mass (m) = 355 g
Initial temperature (Tᵢ) = 95 °C
Final temperature (Tբ) = 140 °C
Heat (Q) tranfered =?
We can calculate the amount of heat transferred by using the following formula:
Q = mC(Tբ – Tᵢ)
Q = 355 × 0.129 (140 – 95)
Q = 45.795 × 45
Q = 2060.775 J
Thus, 2060.775 J of energy was transferred.
Answer:
2060.775 Joules
Explanation:
Write an expression for standard enthalpy of formation using suitable chemical reaction