Formulate the sequence of steps needed to prepare 250.0 mL of a 0.005 M aqueous solution from solid KMnO4 and pure water.

Molarity is a unit that measures how much moles of solute dissolved in a liter of solvent. Molarity expressed using capital M while molarity, a different unit, expressed using lower case m.  

We want to make 0.005 M solution which means we need 0.005 moles of KmnO4 per liter of water. First, we have to calculate how many grams of KMnO4 we need for the solution.

We want to make 250ml solution, so the number of moles of KMnO4 we need will be:  0.005 mol/liter *(250 ml * 1liter/1000ml)= 0.005 mol/liter  * 1/4 liter = 0.00125 moles

The molecular mass of KMnO4 is 158g/mol, so the mass of KMnO4 we need will be:  0.00125 moles *  158g/mol=  0.1975 grams

We know that we need 0.1975 g of KMnO4, now we weigh them and put it inside a dish. After that, we prepare Erlenmeyer or a volumetric flask filled with water half of the volume needed(125ml). Pour the weighted solute into the flask, stir until all solute dissolved.

Then we add water to the container slowly until its volume reaches the 250ml mark.

i am going to put the answers in order i dint feel like typing it out so yeah

a

d

c

b

b

b

a

d

a

b

c

c

c

b

d

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms