1) Chemical reactions produce new substances
Ans (d)
2) The symbol, Δ in a chemical reaction means that heat of supplied to the reaction.
Ans (a)
3) A skeleton equations does not show the reaction stoichiometry, i.e. the relative amounts of reactants and products.
Ans (d)
Answer :
(A) The number of moles of 
ions per liter is, 0.1 moles/L
(B) The number of molecules of 
ion is, 
(C) The pH of the solution will be, 4
<u>Solution for part A :</u>
First we have to calculate the pOH of the solution.
As we know that,
Now we have to calculate the moles of ion per liter.
![pOH=-\log [OH^-]\\\\1=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D%5C%5C%5C%5C1%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=0.1moles/L](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D0.1moles%2FL)
<u>Solution for part B :</u>
First we have to calculate the ion concentration.
![pH=-\log [H^+]\\\\13=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5C13%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=10^{-13}moles/L](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-13%7Dmoles%2FL)
Now we have to calculate the number of molecules of ion
As, 1 mole contains 
number of molecules of ion
So, 
moles contains 
number of molecules of ion
<u>Solution for part C :</u>
![pH=-\log [H^+]\\\\pH=-\log (1\times 10^{-4})](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5CpH%3D-%5Clog%20%281%5Ctimes%2010%5E%7B-4%7D%29)
Answer:
2.9 g/cm³
Explanation:
From the question given above, the following data were obtained:
Mass = 236.376 g
Volume = 81.5 cm³
Density =?
Density can be defined as the mass of a substance per unit volume of the substance. It can be expressed mathematically as:
Density = mass /volume
With the above formula, we can obtain the density of the object as shown below:
Mass = 236.376 g
Volume = 81.5 cm³
Density =?
Density = mass /volume
Density = 236.376 / 81.5
Density = 2.9 g/cm³
Thus, the density of the object is 2.9 g/cm³
Answer:
The total kg from the mixer: 
Evaporated water: 
Jam produced: 
Explanation:
Step by step:
1) Kg of mixture from the mixer
It says that crushed fruit is added to the mixer with the sugar and pectin.
The fruit added is 1000 kg
The sugar added is 1.22 kg sugar/1 kg crushed fruit:
The pectin added is 0.0025 kg pectin/1 kg crushed fruit:
The total kg from the mixer:
2) Evaporated water
To calculate the evaporated water it's important to have in mind that the mix goes from a concentration of 14 wt% to 67 wt%. This difference is because of the evaporated water. So:
Initial: 1000 kg of fruit with 14 wt% of solids
<em>This amount of solids is constant </em>
Final: The mass of solids is the same but now it represents the 67 wt%
and
3) Jam produced
Answer:
(a) barium chloride : BaCl₂ [the cation is barium and anion chloride]
(b) magnesium-nitride
: Mg₃N₂ [Mg is cation and N anion]
(c) sulfur dioxide
: SO₂ [ S is cation and O anion]
(d) nitrogen trichloride : NCl₃
(e) dinitrogen trioxide
: N₂O₃ [two nitrogens and three oxygen]
(f) tin(IV) chloride : SnCl₄
Explanation:
The formula of a compound comprises of the symbol of all the elements.
The element or ion having positive charge is written first followed by anion.
The number of any element is represented as subscript in the formula.
(a) barium chloride : BaCl₂ [the cation is barium and anion chloride]
(b) magnesium-nitride
: Mg₃N₂ [Mg is cation and N anion]
(c) sulfur dioxide
: SO₂ [ S is cation and O anion]
(d) nitrogen trichloride : NCl₃
(e) dinitrogen trioxide
: N₂O₃ [two nitrogens and three oxygen]
(f) tin(IV) chloride : SnCl₄
