Answer: 
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
Digits from 1 to 9 are always significant and have infinite number of significant figures.
All non-zero numbers are always significant.
All zero’s between integers are always significant.
All zero’s after the decimal point are always significant.
All zero’s preceding the first integers are never significant.
Thus has three significant figures
The correct answer is option 2 and 3.
The two scenarios that illustrate the relationship between pressure and volume as described by Boyle’s law are as follows:
2. The volume of an underwater bubble increases as it rises and the pressure decreases.
3. The pressure increases in an inflated plastic bag when the bag is stepped on.
According to Boyle's law, pressure of a gas is inversely proportional to its volume at constant temperature. This means that pressure rises as the volume increases and vice versa.
Options:
monoglycerides
cocamide DEA
folic acid
iron chromium ion
peroxide
lauryl glucoside
disodium phosphate
Answer and Explanation:
The added chemicals are:
- monoglycerides
- folic acid
- iron
- disodium phophates
Monoglycerides are fats added for flavour. Folic cid and iron are vitamins added for nutritional value. disodium phosphate is a food additive for enhancing flavour.
The remaining ingredients are organic based.
Answer: The oxidation state of selenium in SeO3 is +6
Explanation:
SeO3 is the chemical formula for selenium trioxide.
- The oxidation state of SeO3 = 0 (since it is stable and with no charge)
- the oxidation number of oxygen (O) IN SeO3 is -2
- the oxidation state of selenium in SeO3 = Z (let unknown value be Z)
Hence, SeO3 = 0
Z + (-2 x 3) = 0
Z + (-6) = 0
Z - 6 = 0
Z = 0 + 6
Z = +6
Thus, the oxidation state of selenium in SeO3 is +6
Answer:
Mass = 14.64 g
Explanation:
Given data:
Volume of solution = 1.25 L
Molarity of Solution = 0.15 M
Mass of CaF₂ = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
We will calculate the number of moles of CaF₂ and then determine the mass by using number of moles.
0.15 M = number of moles of solute / 1.25 L
number of moles of solute = 0.15 M × 1.25 L
number of moles of solute = 0.1875 mol/L × L
number of moles of solute = 0.1875 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 0.1875 mol ×78.07 g/mol
Mass = 14.64 g
