Answer:
M Na2SO4 sln = 0.8448 M
Explanation:
∴ mass Na2SO4 = 3.00 g
∴ volume soln = 25 mL = 0.025 L
∴ molar mass Na2SO4 = 142.04 g/mol
⇒ mol Na2SO4 = (3.00 g)*(mol/142.04 g) = 0.02112 mol
⇒ M Na2SO4 sln = (0.02112 mol/0.025 L ) = 0.8448 M
Answer:
1.Metals
These are very hard except sodium
These are malleable and ductile pieces
These are shiny
Electropositive in nature
Non-metals
These are soft except diamond
These are brittle and can break down into pieces
These are non-lustrous except iodine
Electronegative in nature
2. The electrochemical series helps to pick out substances that are good oxidizing agents and those which are good reducing agents.In an electrochemical series the species which are placed above hydrogen are more difficult to be reduced and their standard reduction potential values are negative.
3. Arrhenius theory, theory, introduced in 1887 by the Swedish scientist Svante Arrhenius, that acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (H+), and that bases ionize in water to yield hydroxide ions (OH−).
4. The common application of indicators is the detection of end points of titrations. The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values.
Answer: 2 mol
Explanation:
- According to the ideal gas law, One mole of an ideal gas at STP (standard temperature and normal pressure) occupies 22.4 liters.
- Using cross multiplication,
1 mol of (O2) → 22.4 L
? → 43.9 L
Therefore, the number of moles of oxygen in 43.9 L = (43.9 × 1)/ 22.4 = 1.96 mol≈ 2 mol..
Answer: 118.5 grams
Explanation:
Molarity is defined as the number of moles of solute dissolved per liter of the solution.
where,
n= moles of solute
= volume of solution in ml = 500 ml
moles = 0.75
moles of solute =
0.75 =
mass of 
= 118.5 grams
Thus mass of needed to prepare 500 mL of this solution iis 118.5 grams
Answer:
1. decomposition
2. combustion
3.single replacement
4. combination
5. double replacement
Explanation:
1. one compound is split into 2 elements
2. co2 and h20 was the product of the reaction
3. cu is replaced with co
4. 2 compounds become one compound
5. ca is replaced with na and na is replaced with ca
