All categories

3 years ago

SSA PRACTICE QUESTION

Chemistry

1 answer:

Leto [7]3 years ago

4 0

Answer:

The correct answer is - so that other scientists can replicate the experiment and make sure the results are correct or to check accuracy.

Explanation:

The data and procudres are required to be recorded or noted correctly so the experiment and research can be replicate and tested for the accuracy of the experiment by other scientist and researcher.

Mandy also need to note procedure, data, variables and other data correctly for the testing the accuracy and replication of the experiment. The replication is essential to check if every thing is correct and result are error free.

You might be interested in

What's the correct answer?

Andrews [41]

Answer:

smoother and less jagged

Explanation:

6 0

3 years ago

A 1.11 g sample of caffeine, C8H10N4O2, burns in a constant-volume calorimeter that has a heat capacity of 7.85 kJ/K. The temper

VladimirAG [237]

Answer:

401135 kJ

Explanation:

From the balanced quation,

(q/n) = CΔE

Molar heat of combustion = 7.85kJk × (303.81-298.70)k

= 7.85kj × 5.11

= 40.1135kj

4 0

3 years ago

Suppose of barium acetate is dissolved in of a aqueous solution of ammonium sulfate. Calculate the final molarity of barium cati

ollegr [7]

Explanation:

Let us assume that the given data is as follows.

mass of barium acetate = 2.19 g

volume = 150 ml = 0.150 L (as 1 L = 1000 ml)

concentration of the aqueous solution = 0.10 M

Therefore, the reaction equation will be as follows.

$Ba(C_{2}H_{3}O_{2})_{2} \rightarrow Ba^{2+} + 2C_{2}H_{3}O^{-}_{2}$

Hence, moles of $C_{2}H_{3}O^{-}_{2}$ = $2 \times Ba(C_{2}H_{3}O_{2})_{2}$ .......... (1)

As, No. of moles = $\frac{mass}{\text{molar mass}}$

Hence, moles of $Ba(C_{2}H_{3}O_{2})_{2}$ will be calculated as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{2.19 g}{255.415 g/mol}$ (molar mass of $Ba(C_{2}H_{3}O_{2})_{2}$ is 255.415 g/mol)

= $8.57 \times 10^{-3}$

Moles of $C_{2}H_{3}O^{-}_{2}$ = $2 \times 8.57 \times 10^{-3}$

= 0.01715 mol

Hence, final molarity will be as follows.

Molarity = $\frac{\text{no. of moles}}{volume}$

= $\frac{0.01715 mol}{0.150 L}$

= 0.114 M

Thus, we can conclude that final molarity of barium cation in the solution is 0.114 M.

5 0

3 years ago

Methylpropane (complete and condensed structural formulas)

Tcecarenko [31]

Answer:

Here's what I get

Explanation:

1. Complete structural formula

Methylpropane consists of a chain of three carbons with another carbon atom attached to the middle carbon. Enough H atoms are added to give each C atom a total of four bonds.

The complete structural formula is shown below (There is a C atom at each intersection).

2. Condensed structural formula

A condensed structural formula is designed to be typed on one line.

The molecule has three CH₃ groups attached to a single carbon atom, so the condensed structural formula is

(CH₃)₃CH

The formula is also often written CH₃CH(CH₃)CH₃ and as (CH₃)₂CHCH₃.

5 0

3 years ago

In the reaction 2H2O (1)+ 2Cl^- (aq)= H2(g)+Cl2 (g)+ 2OH^-(aq), which substance is reduced?

Oksanka [162]

Answer:- C. H

Explanations:- Reduction is gain of electron. In other words we could say that decrease in oxidation number is reduction.

As per the rules, oxidation number of hydrogen in its compounds is +1(except metal hydrides) and the oxidation number of oxygen in its compounds is -2.

The oxidation number in elemental form is zero.

In $H_2O$ , the oxidation number of H is +1 and oxidation number of O is -2. Oxidation number of Cl in $Cl^-$ is -1. On product side, the oxidation number of hydrogen in $H_2$ is zero and in $OH^-$ the oxidation number of H is +1 and that of O is -2. Oxidation number of Cl in $Cl_2$ is 0.

From above data, Oxidation number of O is -2 on both sides so it is not reduced.

Oxidation number of Cl is changing from -1 to 0 which is oxidation.

Oxidation number of H is changing from +1 to 0 which is reduction.

So, the right choice is C.H

8 0

3 years ago