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3 years ago

What are some ways we can monitor earthquakes ?

Chemistry

1 answer:

a_sh-v [17]3 years ago

5 0

Answer:

Earthquakes are measured using instruments called seismometers, that detect the vibrations caused by seismic waves as they travel through the crust. Also, laser beams can be used

Explanation:

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Blast furnaces extra pure iron from the Iron(IIl)oxide in iron ore in a two step sequence. In the first step, carbon and oxygen

OLga [1]

Answer:

5.9 kg

Explanation:

We must work backwards from the second step to work out the mass of oxygen.

1. Second step

Mᵣ: 55.84

Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂

m/kg: 7.0

(a) Moles of Fe

$\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}$

(b) Moles of CO

$\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}$

However, this is the theoretical yield.

The actual yield is 72. %.

We need more CO and Fe₂O₃ to get the theoretical yield of Fe.

(c) Percent yield

$\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}$

We must use 261 mol of CO to get 7.0 kg of Fe.

2. First step

Mᵣ: 32.00

2C + O₂ ⟶ 2CO

n/mol: 261

(a) Moles of O₂

$\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}$

(b) Mass of O₂

$\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}$

However, this is the theoretical yield.

The actual yield is 71. %.

We need more C and O₂ to get the theoretical yield of CO.

(c) Percent yield

$\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}$

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.

6 0

4 years ago

The table below shows some physical properties of two unknown samples. Physical Properties Sample Mass Solubility (in water) C 2

Vaselesa [24]

The answer would be: The two substances are not the same because the property that is independent of the amount of the sample is different.

The two substances has different solubility which is 36 g/mL and 180 g/mL. The same kind of molecule should have same density and solubility, regardless the mass of the sample. In this case, the substances are not same since it has different solubility.

4 0

4 years ago

Read 2 more answers

How red blood cells different to animal cells

barxatty [35]

Answer:

By contrast, the red blood cells of mammals lack nuclei and other internal structures found in most animal cells. This simplification allows mammal red blood cells to carry more gas-transporting proteins and to squeeze through smaller blood vessels.

Explanation:

4 0

3 years ago

Which of the following radiations consists of a helium nucleus emitted by some radioactive substances? Alpha radiation Beta radi

erica [24]

Answer: Alpha radiation

Explanation: Alpha decay : When a larger radioactive nuclei decays into smaller nuclei by releasing alpha radiation, the mass number and atomic number is reduced by 4 and 2 units respectively.

$_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}Y+_2^4\textrm{He}$

Beta decay : When a larger radioactive nuclei decays into smaller nuclei by releasing beta radiation, the atomic number is increased by 1 unit.

$_Z^A\textrm{X}\rightarrow _{Z+1}^{A}Y+_{-1}^0e$

Gamma decay : When a larger radioactive nuclei decays into smaller nuclei by releasing gamma radiation, the mass number remains same.

$_Z^A\textrm{X}^*\rightarrow _Z^A\textrm{X}+_0^0\gamma$

5 0

3 years ago

Identify each of the following as a representative element or a transition element.

Nady [450]

The Representative elements are the first two relations and the last six relations of the Periodic Table. The Transition elements are in three series in periodic table and they all are metals.
therefore,
A) lithium is Representative element
B) platinum isTransition element
C) promethium isTransition element
D) carbon is Representative element

6 0

4 years ago