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2 years ago

How does the curing basically take place?

Chemistry

1 answer:

Sphinxa [80]2 years ago

4 0

Explanation:

The first involves keeping the surface of the concrete moist by the use ponding, spraying/sprinkling, damp sand or damp hessian.

The second prevents the loss of moisture from the concrete by covering it with polythene sheeting or leaving the formwork in place.

The third involves the use of spray or roller applied curing compounds.

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A reaction was suppose to produce 20 L of gas. Only 12 litters of gas were produced in the lab. What is the percent yield for th

pogonyaev

Answer:

$\boxed {\boxed {\sf 60 \%}}$

Explanation:

Percent yield is a ratio of the actual yield to the theoretical yield. It is found using this formula:

$\% \ yield= \frac {actual \ yield}{theoretical \ yield} *100$

The actual yield is 12 liters, because that was actually produced in the lab.

The theoretical yield is 20 liters, because that was the expected yield.

$\% \ yield= \frac {12 \ L}{20\ L} *100$

$\% \ yield= 0.6*100$

$\% \ yield= 60$

For this reaction, the percent yield is 60%.

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3 years ago

During an experiment, a scientist places a heat lamp above a bowl of water and uses the lamp to heat up the water. How does heat

dlinn [17]

Answer:

Radiation

Explanation:

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3 years ago

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3 , from

Mazyrski [523]

Answer:

troposphere

stratosphere

exosphere

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3 years ago

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1. In the models, what particles do the colored and plain sesame seeds represent? What particles do the poppy seeds represent?

san4es73 [151]

Thank you for posting your question here. Below are the answers to the above questions:

1. The colored sesame seeds represent neutrons, and plain sesame seeds represent protons.
<span>2. The two poppy seeds glued to the fiberfill represent electrons. </span>

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3 years ago

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An analytical chemist weighs out 0.055g of an unknown triprotic acid into a 250mL volumetric flask and dilutes to the mark with

Katarina [22]

Answer:

Mass of the unknown acid is 4.0g

Explanation:

The determine the molar mass of the unknown acid, the steps below can be followed

Firstly, determine the concentration of the acid, the formula below can be used;

ConcA × Va/ConcB × Vb = Na/Nb

Where ConcA is the concentration of the unknown acid

ConcB is the concentration of the NaOH base

Va is the volume of acid and Vb is the volume of base

Since, the titration was said to have reached an equivalent point, it means the number of moles of the acid (Na) was equal to the number of moles of the base (Nb) and thus both will be assumed to be 1

Thus

ConcA × 250/0.13 × 6.6 = 1/1

ConcA = 0.13 × 6.6/250

ConcA = 0.003432M

Then, determine the actual number of moles (n) of the unknown acid used,

ConcA = no of moles of acid/volume of acid (in dm³ or L)

To convert mL to L, we divide by 1000

Hence, 250ml = 0.25L

0.003432 = n/0.25

n = 0.003432 × 0.25

n = 0.01373 moles

To determine the molar mass;

n = mass/molar mass

The mass was given in the question to be 0.055g

Thus

0.01373 = 0.055/molar mass

molar mass = 0.055/0.01373

molar mass = 4.0g

5 0

3 years ago