Soil.
Heterogeneous means is can be separated and soil can be taken apart and separated according to its contents. (Rocks, dirt, grass). <span />
Answer:
5.25g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is shown below:
Na2SiO3 + 8HF → H2SiF6 + 2NaF + 3H2O
From the balanced equation above,
8 moles of HF reacted to produce 2 moles of NaF.
Therefore, 0.5 moles of HF will react to produce = (0.5 x 2)/8 = 0.125 mole of NaF.
Next, we shall convert 0.125 mole of NaF to grams.
This is illustrated below:
Mole of NaF = 0.125 mole
Molar mass of NaF = 23 + 19 = 42g/mol
Mass of NaF =..?
Mass = mole x molar mass
Mass of NaF = 0.125 x 42
Mass of NaF = 5.25g
Therefore, 5.25g of NaF is produced from the reaction.
Answer:
Refinement
Explanation:
The 3R's policy was fundamentally introduced to safeguard the animals from harsh experiments which could change their mental and physical abilities and lead to their extinction one day.
The principles of 3R's (Replacement , Reduction and Refinement) were developed long time ago. It is an strategy to perform more Humane animal research.
These are defined as,
Replacement is a method to avoid or replace the uses of animals.
Reduction is a method to minimize the number of animals used every experiment.
Refinement is a method of minimizing animal suffering and improving welfare.
Explanation:
1)
Mass of NaOH = m
MOlar mass of NaOH = 40 g/mol
Volume of NaOH solution = 1.00 L
Molarity of the solution= 1.00 M
A student can prepare the solution by dissolving the 40. grams of NaOH in is small volume of water and making that whole volume of solution to volume of 1 L.
Upto two significant figures mass should be determined.
2)
(dilution equation)
Molarity of the NaOH solution = 
Volume of the solution = 
Molarity of the NaOH solution after dilution = 
Volume of NaOH solution after dilution= 
A student can prepare NaOH solution of 1.00 M by diluting the 0.500 L of 2.00 M solution of NaOH with water to 1.00 L volume.
Upto three significant figures volume should be determined.
Answer:
C
Explanation:
okay, you need to look at the structures of the particles of matter in the solid, liquid and gas.
- particles in a solid are in fixed positions, where they can only vibrate in those positions ( take a look at ice, or rather, a brick)
- liquids have very small or rather, no spaces between them, but they can slide or rub against each other, like people in a <em>really tight</em> crowd I guess
- gas particles have very large spaces between them and they move randomly. these exibit what's called brownian motion.
- since water particles (and all other liquid particles) have negligible spacings and limited movement, that allows the dye particles to move from a region of high concentration to that of a low concentration. the aim for this is for the mixture/solution to reach an equilibrium, that is the mixture must get to a point where all regions have the same concentration of the dye.
you can refer to your coursebooks :)
correct where wrong please:)
