Answer:
1.155 moles of potassium nitrate are required to make 550 mL of a 2.1M solution.
Explanation:
In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes.
Molarity is a unit of concentration of a solution and indicates the amount of moles of solute that appear dissolved in each liter of the mixture. In other words, the Molarity (M) or Molar Concentration is the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by the following expression:
Molarity is expressed in units (
).
In this case:
- Molarity= 2.1 M
- number of moles of solute= ?
- Volume= 550 mL= 0.550 L (being 1L=1000 mL)
Replacing:
Solving:
number of moles of solute= 2.1 M* 0.550 L
number of moles of solute= 1.155 moles
1.155 moles of potassium nitrate are required to make 550 mL of a 2.1M solution.
Answer:
93.33%
Explanation:
Thorium is a radioactive element with a molecular weight of 232g/mol. Thorium is very stable and can have 14.05 billion years of half-life period. Every half-life passed, the parent compound mass will be decayed by half. If the age of the rock is 1.4 billion years, then the amount of the parent compound will be:r = ½^(time elapsed/half-life)
r = ½^(1.4bil years/14.05 bil years)
r = ½^(0.0996)= 0.9333
r= 93.33%
The rock will have 93.33% of the parent compound and 6.67% of the decayed compound.
<h2>The required "option is d)".</h2>
Explanation:
- Remineralization of enamel is a natural process and is of the same color.
- The saliva contains calcium, phosphate, and fluoride which helps in the neutralisation of acids present in food.
- Remineralization helps in improving the strength and functioning of the tooth by replacing calcium ions and flouride ions which were removed by demineralization.
- It helps in prevention of cavity formation in teeth and strengthens the teeth by replacing loss of calcium ions, phosphate ions, and fluoride by fluorapatite crystals that are more resistant to acids.
- Hence, the remineralized crystal is more resistant to acids.
Answer:
Explanation:
1. A student mixes baking soda and vinegar in a glass. The results are shown at left. ... Yes I do belive that new substances are being formed because there is a chemical reaction between the baking soda and vinegar turning it into a bubbly substances instead of a powder and liquid.
