To run a spectrophotometry experiment, begin by _______ the spectrophotometer and preparing the samples. Be sure to select the correct ________, then run a measurement on the _______ solution. Follow up by running measurements on _______ solutions. Once data is collected, turn off the instrument, clean the area, and discard the samples.
1.
a) cleaning
b) warming up
c) unplugging
2.
a) wavelength
b) transmittance
c) absorbance
3.
a) blank
b) aqueous
c) sample
4.
a) blank
b) aqueous
c) sample

Answer:

For a chemical reaction, the enthalpy of reaction (ΔHrxn) is the difference in enthalpy between products and reactants; the units of ΔHrxn are kilojoules per mole

Answer:

AgNO3 + KI → Agl + KNO3. Double-replacement reaction

Explanation:

Based on solubility rules, Silver, Ag produce an insoluble salt in presence of halides (Fluorides F-, Chlorides Cl-, Iodides, I-, and bromides Br-). That means the mixture of AgNO3 (Ag⁺ ions) with KI (I- ions) produce AgI as insoluble salt.

The reaction is:

And this is a double-replacement reaction where the cations exchange of anion to produce 2 new compounds.

Answer:

AgI + KNO3

Explanation:

double replacement

Answer:

95.9 kg

Explanation:

First we convert 15.0 mi² to m²:

Then we convert 27.0 ft to m:

Now we calculate the total volume of the lake:

Converting 3.20x10⁸ m³ to L:

Now we calculate the total mass of mercury in the lake, using the given concentration:

Finally we convert μg to kg:

Answer:

The molar mass of Beryllium is 9.012182 u

Answer:

23.2 kJ of energy are released by the reaction.

Explanation:

Hello there!

In this case, according to the given information, it turns out firstly necessary for us to calculate the moles of both tin and nitrogen and the produced moles of Sn3N4 product by each reactant as shown below:

[tex]13.1gSn*\frac{1molSn}{119gSn} *\frac{1molSn_3N_4}{3molSn} =0.0367molSn_3N_4\\\\2.715gN_2*\frac{1molN_2}{28gN_2} *\frac{1molSn_3N_4}{2molN_2} =0.0485molSn_3N_4[/tex]

Thus, since 13.1 grams of tin produce the fewest moles of Sn3N4 product, we infer tin is the limiting reactant, and the correct produced energy, due to this reaction is:

[tex]E=632\frac{kJ}{mol\ rxn}*\frac{1mol\ rxn}{1molSn_3N_4}*0.0367mol Sn_3N_4\\\\E=23.2kJ[/tex]

Regards!

Answer:

The U.S government made such an investment because they're most likely to reduce harmful emissions.

Answer:

Colloids

There are two basic methods of forming a colloid: reduction of larger particles to colloidal size, and condensation of smaller particles (e.g., molecules) into colloidal particles. Some substances (e.g., gelatin or glue) are easily dispersed (in the proper solvent) to form a colloid; this spontaneous dispersion is called peptization. A metal can be dispersed by evaporating it in an electric arc; if the electrodes are immersed in water, colloidal particles of the metal form as the metal vapor cools. A solid (e.g., paint pigment) can be reduced to colloidal particles in a colloid mill, a mechanical device that uses a shearing force to break apart the larger particles. An emulsion is often prepared by homogenization, usually with the addition of an emulsifying agent. The above methods involve breaking down a larger substance into colloidal particles. Condensation of smaller particles to form a colloid usually involves chemical reactions—typically displacement, hydrolysis, or oxidation and reduction.

Answer:

1. B

2. A

3. C

4. C

5. D

Explanation:

Soil is regarded as the solid unconsolidated material of the earth crust. Soil is of three different types namely: Sandy soil, clay soil and loamy soil. These three different soil types possess different properties that distinguish them. Some of them are:

- CLAY soil is characterized as having the finest particles and can hold greater amount of water i.e. have a high water holding capacity.

- LOAMY SOIL is the best soil type for planting agricultural crops because it has the highest concentration of nutrients that suited for plant growth.

- loamy, Sandy and clay differ in how we feel when touched i.e. texture, and colour.

- SANDY soils are the kind of soils that are found in Sea shores and beaches.

- Soil is important to living things as it forms part of the earth where animals live, provides the necessary nutrients needed by plants, serves as a place where people live.

Answer:

A positively charged nucleus consisting of protons and neutrons

Explanation:

The atomic nucleus is a positively charged region located at the core of an atom that consists of positively charged protons and neutral neutrons while the negatively charged electrons make up the outer cloud (electrons are therefore not contained in the nucleus).

how

the

Way

of

it's

the Base

Answer:

CO is considered as a product.

Explanation:

A general chemical equation for a combination reaction follows:

To write a chemical equation, we must follow some of the rules:

The reactants must be written on the left side of the direction arrow.

A '+' sign is written between the reactants, when more than one reactants are present.

An arrow is added after all the reactants are written in the direction where reaction is taking place. Here, the reaction is taking place in forward direction.

The products must be written on the right side of the direction arrow.

A '+' sign is written between the products, when more than one products are present.

For the given chemical equation:

are the reactants in the reaction and  are the products in the reaction.

Hence, CO is considered as a product.

Answer:

The hydride ion,H−is a stronger base, so it will abstract a proton from the water. As the water will give protons, so water will work as an acid and an acid-base reaction will take place. Hydride ions get protons from water and form hydrogen gas and hydroxide ions.

Sodium hydride is the chemical compound with the empirical formula NaH. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na+ and H− ions, in contrast to molecular hydrides such as borane, methane, ammonia, and water.

Answer:

AlCl3 + HCl ===> AlCl4 +H-

Answer:

40.4 kJ

Explanation:

Step 1: Given data

Step 2: Calculate the moles corresponding to 55.0 g of CO₂

The molar mass of CO₂ is 44.01 g/mol.

n = 55.0 g × 1 mol/44.01 g = 1.25 mol

Step 3: Calculate the heat (Q) required to sublimate 1.25 moles of CO₂

We will use the following expression.

Q = n × ΔH°sub

Q = 1.25 mol × 32.3 kJ/mol = 40.4 kJ

Answer:

yes

Explanation:

cos of high electron transfer

Answer:

D. having fur that is a similar color to tree barks with algae growing on it

Explanation:

Choice A doesnt make sense because sloths do not change colors, and hanging upside down would not protect you from prey or blend in. D matches the description of a sloth.

Answer:

Having fur that is a similar color to tree barks with algae growing on it.

Explanation:

T=41+273=314 k

M=(12)+(16×2)=44g/mol

d=PM/RT

d=685×44/0.0821×314

d=1169.15 g/L

Answer:

CH2=CH-CH3

Explanation:

One of the ways of preparing alkenes is by dehydration of alcohols using sulphuric acid. The sulphuric acid merely acts as a catalyst in the process.

It begins with the protonation of the -OH group. This is followed by loss of water molecule since water is a good leaving group.

Loss of a proton now completes the mechanism and regenerates the acid catalyst.

The mechanism of dehydration of 2-propanol as well as the product formed in the process is shown in the image attached to this answer.

Answer:

when the explosion happened the matter fussed into elements as the electrons portions Nd notrons were compresed into the elements beacuase hydrogen has 1 nutron proton and electron surronding its core

Answer:

The given molecules are SO2 and BrF5.

Explanation:

Consider the molecule SO2:

The central atom is S.

The number of domains on S in this molecule is three.

Domain geometry is trigonal planar.

But there is a lone pair on the central atom.

So, according to VSEPR theory,

the molecular geometry becomes bent or V-shape.

Hybridization on the central atom is

[tex]sp^{2}[/tex].

Consider the molecule BrF5:

The central atom is Br.

The number of domains on the central atom is six.

Domain geometry is octahedral.

But the central atom has a lone pair of electrons.

So, the molecular geometry becomes square pyramidal.

The hybridization of the central atom is [tex]sp^{3} d^{2}[/tex].

The shapes of SO2 and BrF5 are shown below:

Transition metals

Most transition metals differ from the metals of Groups 1, 2, and 13 in that they are capable of forming more than one cation with different ionic charges. As an example, iron commonly forms two different ions

Answer:

The correct answer is 0.020 M.

Explanation:

To solve this problem, we can use the equation M1V1 = M2V2, where M represents the molarity of the solution and V represents the volume of solution.  Since we are given that the original solution is 50 mL and 0.40 M, these values are V1 and M1, respectively.  The solution after dilution has a volume of 1000 mL, so this value is V2.  We are solving for the molarity after dilution, which represents M2.

If we plug in the values specified above, we get the following:

M1V1 = M2V2

(0.40 M)(50.0 mL) = (M2)(1000.0 mL)

Solving for M2, we get:

M2 = 0.020 M

Notice that our answer has 2 significant figures because 0.40 has 2 significant figures, the least of any values given in the problem.

Therefore, the answer is 0.020 M.

Hope this helps!

Four quantities must be known for a complete physical description of a sample of a gas: temperature, volume, amount, and pressure. ... The height of the mercury column is proportional to barometric pressure, which is often reported in units of millimeters of mercury (mmHg), also called torr.

Answer:

Given total pressure of the gas mixture(hydrogen and helium) is 2.99 atm

Number of moles of hydrogen is ---- 13.2 mol

Number of moles of helium is ---- 19.1 mol

Determine the partial pressure of the helium gas.

Ratio of effusion rates of the two gases.

Explanation:

According to Dalton's law of partial pressures,

partial pressure of a component gas in a mixture is:

partial pressure of a gas = total pressure x mole fraction

mole fraction of helium gas is:

[tex]mole fraction of helium gas = \frac{number of moles of helium gas}{total number of mioles} \\=>mole fraction of He= \frac{19.1mol}{(19.1+13.2)mol} \\=>mole fraction of He = 0.591\\[/tex]

Partial pressure of He gas is:

[tex]Partial pressure of He =mole fraction of He * total pressure\\ =0.591 x 2.99atm\\ =1.77atm[/tex]

Effusion rate of a gas is inversely proportional to its square root of its molecular mass.

[tex]\frac{rate of effusion of H2 gas}{rate of effusion of He gas} =\sqrt{\frac{molar mass of He gas}{molar mass of H2 gas} } \\=> \frac{rate of effusion of H2 gas}{rate of effusion of He gas}=\sqrt{\frac{4g.}{2g} } \\=>\frac{rate of effusion of H2 gas}{rate of effusion of He gas}=1.414:1[/tex]

Hence, rates of effusion of H2:He is 1.414:1.

Answer:

Everything around you can be broken down into smaller particles called atoms. The particles of one substance are all the same and different substances are made up of different particles.

Explanation:

Answer:i believe you are to decompose the formula (i think)