Answer:
the animal
Explanation:
a rodent thas in the ground
Answer:
1.25mole of Mg(OH)₂
Explanation:
The reaction is between Mg(OH)₂ and HCl, this is a neutralization reaction between an acid and a base.
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
The balanced reaction equation is given above.
2 mole of HCl reacts with 1 mole of Mg(OH)₂
So, 2.5mole of HCl will react with
= 1.25mole of Mg(OH)₂
The number of moles of Mg(OH)₂ is given as 1.25mol
Answer:

Explanation:
The formula for molality is:

There are 0.210 moles of KBr and 0.075 kilograms of pure water.

Substitute the values into the formula.

Divide.

The molality is <u>2.8 moles per kilogram</u>
Answer:
K₂CrO₅
Explanation:
The empirical formula is the simplest formula of a compound. To find the empirical formula, we follow the procedure below:
Elements Potassium Chromium Oxygen
Mass 6.52 4.34 5.34
Molar mass 39 60 16
Number of moles 6.52/39 4.34/60 5.34/16
0.167 0.072 0.333
Divide through by
the smallest 0.167/0.072 0.072/0.072 0.333/0.072
2.3 1 4.6
2 1 5
Empirical formula K₂CrO₅
In rubidium oxide - Rb₂O , the ions are Rb⁺ and O²⁻
Rb is a group one element with one valence electron. To become stable it loses its outer electron to gain a complete outer shell.
Electronic configuration of Rb is - 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s¹
Once it loses its valence electron the configuration is;
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶
The noble gas with this configuration is Krypton - Kr
Oxygen electron configuration is 1s² 2s² 2p⁴
Once it gains 2 electrons the configuration is - 1s² 2s² 3p⁶
The noble gas with this configuration is Neon - Ne