The H+ concentration in the lake has increased as a result of the acid rain.
The original pH of the lake was 7, which mean the water is neutral, but due to the acid rain, it drops to 5. This means, that the water has become acidic and how have more hydrogen ion. The H+ concentration in the lake has 100 times compares with its original pH.
The solution is here,
given mass of copper wire(m)=25 g
no. of moles in given mass of Cu=0.393
a) no. of atoms= no. of moles×avogardo's number
=0.393×6.023×10^23=2.36 ×10^23 atoms
b) 25 g of Cu wire has 0.393 moles
so 200 g of Cu wire has 0.393/25 × 200=3.144 mol.
no. of atoms= 3.144×2.023×10^23=1.89×10^24 atoms.
c) 25 g of Cu wire has 2.36×10^23 atoms
so 5 g of Cu wire has (2.36×10^23)/25 × 5
=4.72×10^22 atoms
( b can also be solve like c)
Answer:
(a) W
(b) X
(c) Y
Explanation:
Let's consider the following table with melting and boiling points for 4 substances.
Substance Melting Point (°C) Boiling Point (°C)
W -7 60
X 660 2500
Y 180 1330
Z 115 445
Let's consider that:
- Below the melting point, a substance is solid.
- Between the melting and the boiling point, a substance is liquid.
- Above the boiling point, a substance is gas.
(a) Which substance is a gas at 100°C?
At 100 °C, W is above the boiling point
(b) Which substance is a liquid for the largest range of temperature?
The largest difference between the melting point and the boiling point is that of X: 2500 - 660 = 1840.
(c) Which substance is liquid at 1000 °C and a gas at 2000°C?
Y is between the melting and the boiling point at 1000 °C and above the boiling point at 2000 °C.
Answer:
Ở các đơn vị hành chính tại Việt 4 điểm Nam đều tổ chức cấp chính quyền địa phương gồm có Hội đồng nhân dân và ủy ban nhân dân. Nhận định trên đúng hay sai? Tại sao?
Answer:
A system is in equilibrium when the rate of the forward reaction is equal to the rate of the reverse reaction.
Explanation:
In a system in equilibrium, the rupture and formation of new bonds from the formation and decomposition of substances must have the same reaction rate. Thanks to equal speeds we can say that a system in equilibrium is dynamic and in general every system tends to move spontaneously towards equilibrium. The environment never interferes.
For example.
N2 (g) + 3H2 (g) ---> 2NH3 (g) formation
2NH3 ----> N2 (g) + 3H2 (g) decomposition
N2 (g) + 3H2 (g) <------> 2NH3 (g) In equilibrium
