Which of these would most likely be considered a pure substance?

Formula of a copper (II)sulfate hydrate lab

s344n2d4d5 [400]

Answer:

Weigh the empty crucible, and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate. Record all weighings accurate to the nearest 0.01 g.

Support the crucible securely in the pipe-clay triangle on the tripod over the Bunsen burner.

Heat the crucible and contents, gently at first, over a medium Bunsen flame, so that the water of crystallisation is driven off steadily. The blue colour of the hydrated compound should gradually fade to the greyish-white of anhydrous copper(II) sulfate. Avoid over-heating, which may cause further decomposition, and stop heating immediately if the colour starts to blacken. If over-heated, toxic or corrosive fumes may be evolved. A total heating time of about 10 minutes should be enough.

Allow the crucible and contents to cool. The tongs may be used to move the hot crucible from the hot pipe-clay triangle onto the heat resistant mat where it should cool more rapidly.

Re-weigh the crucible and contents once cold.

Calculation:

Calculate the molar masses of H2O and CuSO4 (Relative atomic masses: H=1, O=16, S=32, Cu=64)

Calculate the mass of water driven off, and the mass of anhydrous copper(II) sulfate formed in your experiment

Calculate the number of moles of anhydrous copper(II) sulfate formed

Calculate the number of moles of water driven off

Calculate how many moles of water would have been driven off if 1 mole of anhydrous copper(II) sulfate had been formed

Write down the formula for hydrated copper(II) sulfate.

#*#*SHOW FULLSCREEN*#*#

Explanation:

7 0

3 years ago

Name the compounds( Please answer only if you know)

IRISSAK [1]

Answer

2-methyl-2-pentene

Explanation:

1. Identify the group that takes precedence in this case alkene hence this molecule is an alkene with a methyl group side chain.

2.Find the longest carbon chain where the functional group(alkene group in this case) has the lowest Carbon number

3.What are the side groups? One side group can be seen at carbon 2 this group is methyl

4. Naming, number separated by "," and number from letters by "-" so the compound should be

2-methyl-2-pentene

8 0

3 years ago

How many moles of Cu do you need to react with 12 moles of O2? 2Cu(s) + O2(g) 2CuO(s)

zzz [600]

Answer:

24 mol Cu

General Formulas and Concepts:

Chemistry

Stoichiometry

Explanation:

Step 1: Define

RxN: 2Cu (s) + O₂ (g) → 2CuO (s)

Given: 12 moles O₂

Step 2: Stoichiometry

$12 \ mol \ O_2(\frac{2 \ mol \ Cu}{1 \ mol \ O_2} )$ = 24 mol Cu

Step 3: Check

We are given 2 sig figs.

Our final answer is in 2 sig figs, so no need to round.

3 0

3 years ago

For the hypothetical reaction: A + B ---> 2C, write an expression that relates the disappearance of A and B to the appearance

forsale [732]

Answer:

Rate expression has been given below

Explanation:

According to the given equation, 1 molecule of A reacts with 1 molecule of B and produces 2 molecules of B at a time.

So, rate of disappearance of both A and B are one half of rate of appearance of B

Hence rate expression can be represented as:

$Rate=\frac{-\Delta [A]}{\Delta t}=\frac{-\Delta [B]}{\Delta t}=\frac{1}{2}\frac{\Delta [C]}{\Delta t}$

where $\frac{-\Delta [A]}{\Delta t}$ is rate of disappearance of A, $\frac{-\Delta [B]}{\Delta t}$ is rate of disappearance of B and $\frac{\Delta [C]}{\Delta t}$ rate of appearance of C