Although frequent handling and living near seawater can cause pewter to oxidize and discolor, pewter does not tarnish like silver and copper. Warm, soapy water can be used to clean pewter. After rinsing, the metal can be towel dried.
In water, is pewter safe?Lead-free and secure to use, modern pewter. It is primarily comprised of tin, with some antimony and copper. The goods are guaranteed to be lead-free and are perfectly safe to be used for all types of food and beverages, claims one maker.
Lead content in antique pewter?30 percent lead and 70 percent tin were the main components of ancient pewter. With time, this pewter, sometimes known as black metal, darkened significantly, and lead rapidly leached out when it came into touch with acidic foods.
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How to determine the relative rates of reactant disappearance and product appearance using reaction stoichiometry
Answer:
For example, the relative rate of a reaction at 20 seconds will be 1/20 or 0.05 s -1, while the average rate of reaction over the first 20 seconds will be the change in mass over that period, divided by the change in time.
Explanation:
Hope it helps u
FOLLOW MY ACCOUNT PLS PLS
The gas phase decomposition of phosphine at 120 °C
PH3(g)1/4 P4(g) + 3/2 H2(g)
is first order in PH3 with a rate constant of 1.80×10-2 s-1.
If the initial concentration of PH3 is 8.48×10-2 M, the concentration of PH3 will be 2.45×10-2 M after
s have passed.
Answer:
The decreasing in concentration occurs after 69.0s
Explanation:
A first order reaction follows the equation:
Ln [A] = -kt + ln[A]₀
Where [A] is the concentration of the reactant after time t
k is rate constant of the reaction
And [A]₀ is the initial concentration of the reactant
Replacing:
Ln 2.45x10⁻²M = -1.80x10⁻²s⁻¹*t + ln8.48x10⁻²
-3.709 = -1.80x10⁻²s⁻¹*t -2.467
-1.2416 = -1.80x10⁻²s⁻¹*t
69.0s = t
The decreasing in concentration occurs after 69.0s
A student weighs an empty flask and stopper and finds the mass to be 53.256 g. She then adds about 5 mL of an unknown liquid and heats the flask in a boiling water bath at 98.8°C. After all the liquid is vaporized, she removes the flask from the bath, stoppers it, and lets it cool. After it is cool, she momen- tarily removes the stopper, then replaces it and weighs the flask and condensed vapor, obtaining a mass of 53.780 g. The volume of the flask is known to be 231.1 mL. The absolute atmospheric pressure in the laboratory that day is 728 mm Hg. a. What was the pressure of the vapor in the flask in atm?
Answer:
a. The pressure in the flask open to the atmosphere during the vaporization of the unknown liquid is equal to the prevailing atmospheric pressure equivalent to 0.957734 atm
Explanation:
The mass of the empty flask and stopper, m = 53.256 g
The volume of the unknown liquid she adds = 5 mL
The temperature of the water in which she heats up the flask = 98.8 °C = 371.95 K
The mass of the flask and the condensed vapor = 53.780 g
The volume of the flask, V = 231.1 mL
The atmospheric pressure, P = 728 mm Hg
a. We note that the student stoppers the flask after all the liquid has evaporated. Therefore, given that the flask was open to the atmospheric pressure as the liquid evaporates, the pressure of the vapor in the flask is equal to the prevailing atmospheric pressure, or 728 mmHg
Using a calculator, 728 mm Hg is equivalent to 0.957734 atm.
Which of the following bonds is classified as a polar bond?
A K-CI
B Br-Br
C Si-F
D S-O
WILL MARK BRAINLIST
Answer:
the answer is b
Explanation:
the answer is b
Compound of KCl has a polar bond as there is a electronegativity difference between potassium and chlorine atoms.
What is a compound?
Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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During
the
school
year,
1.3
x
102
students
participate
in
football,
and
.5
x
102
participate
in
soccer.
What
is
the
total
number
of
students
that
participate
in
football
4. Calculate the heat energy needed to heat 25.0 g of water from 13.0°C to 18.0°C. Use chart above for specific heat of water. Use units and show all work.
Answer: I go search some information
Explanation:I come back with a answer
A scientist is designing a device that will kill harmful cells in the human body using high-energy waves. Which type of wave would be most effective
А
X-rays would be the best choice because they have a long wavelength and a low frequency
accomplishing this goal?
B
Radio waves would be the best choice because they have a long wavelength and a low frequency
Gamma rays would be the best choice because they have a short wavelength and a high frequency
D
Infrared waves would be the best choice because they have a short wavelength and a high frequency
C2021 Illuminate Education Inc.
Tin
Type here to search
O
BH
Answer:
gamma rays
Explanation:
gamma Ray's have the highest frequency
Si Hecho Dos Cubos de Hielo En Un Vaso Con Agua Señalo Donde Quedo El Nivel Del Agua, Luego A Pasar El Tiempo Dejo Que Se Derritan Los Cubos De Hielo El Nivel Del Agua Aumenta??
Answer:
Ver explicacion
Explanation:
Técnicamente, cuando el hielo se derrite, ocupa aproximadamente el mismo volumen de agua que es igual a la masa de agua desplazada antes de que el hielo se derrita. Esto es posible solo cuando se ignora el cambio en la densidad del agua.
Sin embargo, si tenemos en cuenta el ligero cambio en la densidad del agua, se puede demostrar que el volumen de hielo es mayor que el del agua líquida porque el agua se expande cuando se congela.
Esto significa que el volumen de agua disminuye cuando el hielo se derrite.
I have a bowling ball hanging from a chain in my room. What two forces are acting on the bowling
ball?
Answer:
Gravity and the chain is holding it up not sure what it is called. Also if you want free points go to my answers and look for a friday nigt funkin rp answer but anwer if you want to rp and if you know what it is
Explanation:
Answer:
Kinetic & Potential Energy
Explanation:
Kinetic Energy: Energy which a body possesses by virtue of being in motion.
Potential Energy: The energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors
Hope this helps! Have a good day/or night!
P.S: Sorry if I'm wrong I tried my best. Best wishes!!!
What does this image represent?
A. Linear molecule with one domain
B. Linear molecule with two domains
C. Tetrahedral molecule with four domains
D. Trigonal planar molecule with three domains
Answer: A.
Explanation:
Answer:
A. Linear molecule with one domain.
Hope this helps! :)
Explanation:
PLEASE HELP AND DONT YOU DARE GIVE ME THE LINK
The fact that animals are the only kingdom that has muscle tissue demonstrates a contrast between which of the
following?
animals and humans
animals and protozoans
animals and other living things
animals and insects
Answer:
animals and other living things
Explanation:
All living organisms have been classified and grouped into a hierarchical system of classification. Kingdom is the highest level in this system comprising of 6 other levels. However, there are different kingdoms that harbors different organisms. The kingdoms are: animalia, plantae, protista, monera, fungi etc.
However, among other kingdom of organisms, organisms in the Kingdom Animalia are the only ones that possesses muscle tissues etc. This shows a contrast between animals and other living things.
how many moles of sodium phosphate are required to make 7.5 moles of sodium nitrate in 2Na3PO4+3Be(NO3)=6NanO3+Be3(PO4)2
Answer:
2.5 moles of sodium phosphate
Explanation:
3 Pb(NO3)2 + 2 Na3PO4 → Pb3(PO4)2 + 6 NaNO3
6 (moles in the reaction)- 7.5(moles in the task)
2 (moles in the reaction)- x (moles in answer) ⇒6x = 2*7.5 ⇒ x = 15/6=2.5 (moles)
Which of the following terms describes the area where the Himalaya Mountains formed?
A.)Convergent Boundary
B.)Transform Boundary
C.)Divergent Boundary
B.)Subduction Zone
Answer:
Convergent Boundary describes the area where himalayan mountains formed.
NEED ANSWERS NOWWWWW
Answer:
Explanation:
Observation 1 is correct because the crystals are just turning into water. They can be frozen back.
In a titration, what is the significance of the endpoint?
Answer:
Explanation:
the addition of an indicator to the analyte solution helps us to visually spot the equivalence point in an acid-base titration. Endpoint: refers to the point at which the indicator changes color in an acid-base titration.
Graduated cylinder‘s
Help pleaseee.... :(
Answer:
D= .7
C= 1.25
B= 2.2
A= 3.6
How many moles are in 8.3 x 10^23 molecules of H2O?
Answer:You multiply avogadro's number to what you were given.
8.30x10^23 * 6. 0221409x10^23
=1.357*10^25
Explanation:
What is the mass of an object with a net force of 10 N accelerating at 2 m/s^2??
Answer:
5kg
Explanation:
Force = Mass x acceleration
F = ma
m = F/a = 10N/2m/s^2
m = 10/2 = 5kg
The standard unit for mass = Kilogram
What kind of rock can be broken
down to make sand?
Answer:
sandstone
Explanation:
Sandstone is a mineral rock made of small particles.
How many grams are there in 2.30x10^24 atoms of silver?
Answer:
107.8682 grams.
Explanation:
number of elments in hcooh
in what order were the sun and earth created according to both the younger theory and the older theory
answer: the earth orbits around the sun for 365 while getting older to the young theory.
Answer:
The older theory was that the sun (and other planets) revolved around earth and the new theory is that the earth (and other planets) revolved around the sun.
Explanation:
H2CO: → H2O + CO2
Answer the following question about the equation above.
1. How many atoms of Hydrogen are in the reactant?
2. How many atoms of Carbon are in the reactant?
3. How many atoms of Oxygen are in the reactant?
4. How many atoms of Hydrogen are in the product?
5. How many atoms of Oxygen are in the product?
6. How many atoms of Carbon are in the product?
7. Does the number of atoms of each element on the reactant side match that of the product side?
Answer:
1) 2
2) 1
3)1
4) 2
5)3
6)1
7)yes except Oxygen
What does a positive H look like on a potential energy diagram?
Answer:
D because i did this last week and got it right.
A positive H indicates that the potential energy of products is higher than the potential energy of reactants.
What is a potential energy diagram?A potential energy diagram is a diagram which shows the energy content of reactants and products as well as the energy changes that occur in a reaction.
A positive H in a reaction indicates that the reaction is endothermic and that products have a higher potential energy than reactants.
Therefore, a positive H indicates that tje potential energy of products is higher than the potential energy of reactants.
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The law of reflection states that the angle of incidence and the angle of reflection are always
Answer:
The law of reflection states that the angle of incidence and the angle of reflection are always equal.
no.of elements in KMnO4
Answer:
3 three
Explanation:
potassium (K), manganese (Mn), and oxygen (O).
Answer:
3 different elements (7 in total as there are 4 oxygens (The answer is either one of these))
Explanation:
6th grade science Major grade plz help ASAP
Answer: An organism is part of a community
Which of the following uses electrical energy?
A washing machine
The sun
A plant
A cat
Answer:
★ B. A washing machine.
Explanation:
What's Electrical energy?
Electrical energy is energy derived from electric potential energy or kinetic energy. When used loosely, electrical energy refers to energy that has been converted from electric potential energy.
How does the rate of a chemical reaction change if the concentration of both reactants increases 4 times?
2NO + O2 → 2 NO2
Answer: The rate will increase 32 times if the concentration of both reactants increases 4 times
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
For the reaction : [tex]2NO+O_2\rightarrow 2NO_2[/tex] [tex]rate=k[NO]^2[O_2]^1[/tex]
k= rate constant
order with respect to [tex]NO_2[/tex] = 2
order with respect to [tex]O_2[/tex] = 1
Thus on increasing the concentration of reactants 4 times :
[tex]rate'=k[4\times NO]^2[4\times O_2]^1[/tex]
[tex]rate'=k\times 8\times 4\times [NO]^2\times [O_2]^1[/tex]
[tex]rate'=32\times rate[/tex]
Thus rate will increase 32 times if the concentration of both reactants increases 4 times