Answer:
4.88 Cals per degree celsius
Explanation:
We have taken heat of fusion of ice = 80 cals / g
We have taken speciic heat of water = 1 cal/g per degree celsius
In this experiment , let the heat capacity of calorimeter be X.
Heat gained by ice
heat gained in melting + heat gained in getting warmed
= mass x latent heat + mass x specific heat x rise in temperature
= 17.69 x 80 + 17.69 x 1 x ( 12.9 - 0 )
= 1643.4 Cals
Heat lost by water
= mass x specific heat x fall in temperature
98.67 x 1 x ( 28.77 - 12.9 )
= 1565.89 Cals
Heat lost by calorimeter
heat capacity x fall in temperature
X x ( 28.77 - 12.9 )
Heat gained = heat lost
1643.4 = 1565.89 +15.87X
X = 4.88 Cals per degree celsius
neutrons?
Answer:
Subtracting the number of protons from the atomic mass.
Answer:
Subtract Protons
Explanation:
Since the vast majority of atom's mass is found it's protons and neutrons, Subtracting the Number of Protons ( i.e. the atomic number ) from the atomic mass will give you the calculated number of neutrons in a atom,
B. mixtures
C. compounds.
2. The forces that hold atoms together in combinations are called
A. energy bonds.
B. nuclear bonds.
C. chemical bonds.
3. Every electron has a
A. neutral charge.
B. positive charge.
C. negative charge.
4. The exact positions of the electrons in an atom cannot be determined because
electrons are always
A. moving
B. sharing.
C. changing
5. Compared with electrons that are closer to the nucleus, those that are farther
away have
A. less energy
B. more energy
C. equal energy
question no 1 answer is compounds
Elements combine to form millions of compounds. The force holding atoms together in these combinations are chemical bonds. Each electron has a negative charge, electrons are always moving, and have more energy the farther they are from the nucleus.
The elements can combine in many ways to create compounds, which amount to millions. When atoms connect or adhere to each other to shape those compounds, it happens through chemical bonds. In an atom, each electron has a negative charge, a characteristic that's vital for the creation of chemical bonds. Electrons are in constant movement, which means we cannot exactly determine their positions. As for the energy level of these electrons, those farther away from the nucleus have, in general, more energy than the ones located closer to the nucleus.
#SPJ3
ductility
high melting point
low boiling point
malleability
Answer : The correct options are, brittleness and high melting point
Explanation :
Ionic compound : Ionic compounds are the compounds which are formed when a metal cation bonded with non-metal anion. The metal cation and non-metal anion bonded with an electrostatic force of attraction.
The properties of ionic compounds are :
Ionic compounds are brittle and hard. They breaks easily into small pieces.
They have high melting point and boiling point.
They conduct electricity in liquid state not in solid state.
Hence, the brittleness and high melting point properties are the characteristic of ionic compounds.
Some characteristics of Ionic compounds by Mimiwhatsup: brittle, high melting point, conducts electricity when molten or dissolved in water.
Answer : The concentration of ion, pH and pOH of solution is, , 4.98 and 9.02 respectively.
Explanation : Given,
Concentration of ion =
pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.
The expression used for pH is:
First we have to calculate the pH.
The pOH of the solution is, 9.02
Now we have to calculate the pH.
The pH of the solution is, 4.98
Now we have to calculate the concentration.
The concentration is,
Answer:
pOH = 9.022, [H⁺] = 1.5×10⁻⁵ M, pH = 4.978
Explanation:
Given: [OH⁻] = 9.5 × 10⁻¹⁰ M, T= 25°C
As, pOH = - log [OH⁻]
⇒ pOH = - log (9.5 x 10⁻¹⁰) = 9.022
The self-ionisation constant of water is given by
Kw = [H⁺] [OH⁻] and pKw = pH + pOH
Since, at room temperature (25°C): Kw = 1.0 × 10⁻¹⁴ and pKw = 14.
Therefore, Kw = [H⁺] [OH⁻] = 1.0 × 10⁻¹⁴
⇒ [H⁺] = (1.0 × 10⁻¹⁴) ÷ [OH⁻] = (1.0 ×10⁻¹⁴) ÷ [9.5 × 10⁻¹⁰] = 0.105 ×10⁻⁴ = 1.5×10⁻⁵ M
also,
pH + pOH = pKw = 14
⇒ pH = 14 - pOH = 14 - 9.022 = 4.978
2) However, when additional aqueous hydroxide is added the precipitate redissolves forming a soluble Pb(OH)42-(aq) complex ion
Answer: The chemical equations are given below.
Explanation:
The chemical equation for the reaction of lead nitrate and sodium hydroxide follows:
By Stoichiometry of the reaction:
1 mole of aqueous solution of lead nitrate reacts with 2 moles of aqueous solution of sodium hydroxide to produce 1 mole of solid lead hydroxide and 2 moles of aqueous solution of sodium nitrate.
The chemical equation for the reaction of lead hydroxide and hydroxide ions follows:
By Stoichiometry of the reaction:
1 mole of lead hydroxide reacts with 2 moles of aqueous solution of hydroxide ions to produce 1 mole of aqueous solution of tetra hydroxy lead (II) complex
Hence, the chemical equations are given above.
The balanced chemical equation for each of the reactions is as follows:
A chemical equation is said to be balanced when the number of atoms of each element on both sides of the equation are the same.
According to this question, when aqueous sodium hydroxide is added to a solution containing lead(II) nitrate, a solid precipitate forms. The balanced equation are as follows:
Pb(NO3)2(aq) + 2NaOH(aq) → 2 NaNO3(aq) + Pb(OH)2(s)
Also, when additional aqueous hydroxide is added the precipitate redissolves forming a soluble Pb(OH)42-(aq) complex ion. The balanced equation is as follows:
Pb(OH)2 + 2OH- → Pb(OH)42-
Learn more about balanced equation at: brainly.com/question/1301642
O To determine trends
O To simplify results
O Both B and C
O All of the above
Answer:
b and c
Explanation:
the problem was solved through the experiment and tested