Giúp em với mị người

The formula for speed (S) is S=D/T where S is speed, D is distance and T is time.

sergij07 [2.7K]

Not 100% sure but I think 40 seconds

4 0

3 years ago

Alum is a compound used in a variety of applications including cosmetics, water purification, and as a food additive. It can be

mylen [45]

yield = 52.23 %

Explanation:

We have the following chemical reaction:

2 Al (s) + 2 KOH (aq) + 4 H₂SO₄ (aq) + 10 H₂O → 2 KAl(SO₄)₂·12 (H₂O) (s) + 3 H₂ (g)

mass of aluminium = mass of bottle with aluminium pieces - bottle mass

mass of aluminium = 10.8955 - 9.8981 = 0.9974 g

mass of alum = mass of bottle with final product - bottle mass

mass of alum = 19.0414 - 9.8981 = 9.1433 g

number of moles = mass / molecular weight

number of moles of aluminium = 0.9974 / 27 = 0.03694 moles

number of moles of alum (practical) = 9.1433 / 474 = 0.01929 moles

To calculate the theoretical quantity of alum that should be obtained from 0.03694 moles of aluminium we devise the following reasoning:

if 2 moles of aluminium produce 2 moles of alum

then 0.03694 moles of aluminium produce X moles of alum

X = (0.03694 × 2) / 2 = 0.03694 moles of alum (theoretical)

yield = (practical quantity / theoretical quantity) × 100

yield = (0.01929 / 0.03694) × 100

yield = 52.23 %

Learn more about:

reaction yield

brainly.com/question/7786567

#learnwithBrainly

5 0

3 years ago

Gold has a density of 1,200 lb./ft. What is the density of gold in g/em? For conversion factors use I lb. 453.6 g, and l inch-2.

Jlenok [28]

<u>Answer:</u> The density of gold in $g/cm^3$ is $19.22g/cm^3$

<u>Explanation:</u>

Density is defined as the ratio of mass of the object and volume of the object. Mathematically,

$\text{Density}=\frac{\text{Mass of the object}}{\text{Volume of the object}}$

We are given:

Density of gold = $1200lb/ft^3$

Using conversion factors:

1 lb = 453.6 g

1 feet = 12 inches

1 inch = 2.54 cm

Converting given quantity into $g/cm^3$ , we get:

$\Rightarrow (\frac{1200lb}{ft^3})\times (\frac{453.6g}{1lb})\times (\frac{1ft}{12inch})^3\times (\frac{1inch}{2.54cm})^3\\\\\Rightarrow 19.22g/cm^3$

Hence, the density of gold in $g/cm^3$ is $19.22g/cm^3$

6 0

3 years ago

-3 × 4=? ....................

blagie [28]

Answer:

-12

Explanation:

a negative times a positive is negative

8 0

3 years ago

Read 2 more answers

Will mark brilliant pls help question is above

Degger [83]

Answer:

a.) The garden plants provide energy to all the other organisms. While not every organism consumes garden plants directly, every organism's food lineage can be traced to garden plants. For instance, while ground beetles do not directly consume garden plants, they do eat snails, and snails eat garden plants.

b.) The slug population might increase is the aphid population decreased because there would be less competition for food resources. Both populations consume garden plants, and there is only a finite number of garden plants. Therefore, there is a limit that each population can consume. If there were less aphids eating the garden plants, there would be more left for the slugs. Less starving slugs would lead to greater reproduction and thus a higher slug population.

4 0

1 year ago