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3 years ago

A higher temperature of fresh concrete results in a __________ hydration of cement.

Chemistry

1 answer:

Readme [11.4K]3 years ago

4 0

Answer:

more rapid

Explanation:

A higher temperature of fresh concrete results in a more rapid hydration of cement. This causes reduction in the setting time of the cement, also known as accelerated setting of the cement.

It also reduces the workability of the concrete; as it makes the movement of aggregates harder by reducing the lubricating effect of the cement.

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Which college classes would a student most likely take to become an oceanographer? Select 4 choices.

Setler [38]

Answer:

marine biology

coastal ecology

astronomy

meteorology

Explanation:

As a college student, to study oceanography one will have to take classes in the field of marine biology, coastal ecology, astronomy and meteorology.

An oceanographer is someone or a professional that studies the ocean in order have more scientific knowledge about them.

Oceanography is a merger of geology, biology, chemistry, physics as it pertains to the ocean.

There is no need to study human anatomy to study oceanography.
Marine biology and coastal ecology deals with study of life forms in their marine environment.
Astronomy and meteorology helps to gain insight about the formation of the ocean and how weather relates to the ocean.

5 0

3 years ago

A eudiometer contains a 65.0 ml sample of a gas collected

SCORPION-xisa [38]

Answer:

53.1 mL

Explanation:

Let's assume an ideal gas, and at the Standard Temperature and Pressure are equal to 273 K and 101.325 kPa.

For the ideal gas law:

P1*V1/T1 = P2*V2/T2

Where P is the pressure, V is the volume, T is temperature, 1 is the initial state and 2 the final state.

At the eudiometer, there is a mixture between the gas and the water vapor, thus, the total pressure is the sum of the partial pressure of the components. The pressure of the gas is:

P1 = 92.5 - 2.8 = 89.7 kPa

T1 = 23°C + 273 = 296 K

89.7*65/296 = 101.325*V2/273

101.325V2 = 5377.45

V2 = 53.1 mL

6 0

3 years ago

First to answer both CORRECTLY gets brainleist!

madam [21]

Answer: I am actually studying about Stars, so I got you.

3. As the temperature of a star Increases, it's luminosity increases.

As the temperature of a star decreases, it's luminosity decreases.

4. Hot and Bright. The bigger the star, the hotter it gets is from what I learned.

4 0

3 years ago

Read 2 more answers

Five million gallons per day (MGD) of wastewater, with a concentration of 10.0 mg/L of a conservative pollutant, is released int

hjlf

Answer:

a) The concentration in ppm (mg/L) is 5.3 downstream the release point.

b) Per day pass 137.6 pounds of pollutant.

Explanation:

The first step is to convert Million Gallons per Day (MGD) to Liters per day (L/d). In that sense, it is possible to calculate with data given previously in the problem.

Million Gallons per day $1 MGD = 3785411.8 litre/day = 3785411.8 L/d$

$F_1 = 5 MGD (\frac{3785411.8 L/d}{1MGD} ) = 18927059 L/d\\F_2 =10 MGD (\frac{3785411.8 L/d}{1MGD} )= 37854118 L/d$

We have one flow of wastewater released into a stream.

First flow is F1 =5 MGD with a concentration of C1 =10.0 mg/L.

Second flow is F2 =10 MGD with a concentration of C2 =3.0 mg/L.

After both of them are mixed, the final concentration will be between 3.0 and 10.0 mg/L. To calculate the final concentration, we can calculate the mass of pollutant in total, adding first and Second flow pollutant, and dividing in total flow. Total flow is the sum of first and second flow. It is shown in the following expression:

$C_f = \frac{F1*C1 +F2*C2}{F1 +F2}$

Replacing every value in L/d and mg/L

$C_f = \frac{18927059 L/d*10.0 mg/L +37854118 L/d*10.0 mg/L}{18927059 L/d +37854118 L/d}\\C_f = \frac{302832944 mg/d}{56781177 L/d} \\C_f = 5.3 mg/L$

a) So, the concentration just downstream of the release point will be 5.3 mg/L it means 5.3 ppm.

Finally, we have to calculate the pounds of substance per day (Mp).

We have the total flow F3 = F1 + F2 and the final concentration $C_f$ . It is required to calculate per day, let's take a time of t = 1 day.

$F3 = F2 +F1 = 56781177 L/d \\M_p = F3 * t * C_f\\M_p = 56781177 \frac{L}{d} * 1 d * 5.3 \frac{mg}{L}\\M_p = 302832944 mg$

After that, mg are converted to pounds.

$M_p = 302832944 mg (\frac{1g}{1000 mg} ) (\frac{1Kg}{1000 g} ) (\frac{2.2 lb}{1 Kg} )\\M_p = 137.6 lb$

b) A total of 137.6 pounds pass a given spot downstream per day.

4 0

3 years ago

Opal is a hydrated form of silica. If a laboratory analysis of a sample of opal reveals it to contain29.2% Si, 33.3%O, and 37.5%

ZanzabumX [31]

Let us assume that there is a 100g sample of Opal. The masses of each element will be:
29.2g Si
33.3g O
37.5g H2O
Now we divide each constituent's mass by its Mr to get the moles present
Si: (29.2 / 28) = 1.04
O: (33.3 / 16) = 2.08
H2O: (37.5 / 18) = 2.08
Now we divide by the smallest number and obtain:
Si: 1
O: 2
H2O: 2
Thus, the empirical formula of Opal is:
SiO2 . 2H2O

8 0

3 years ago