All categories

3 years ago

Luminol is used in a preliminary test for ___?

Chemistry

1 answer:

Klio2033 [76]3 years ago

5 0

Answer:

It's usually used to test for blood

Explanation:

Polices often use luminol to find blood :)

Brainliest???

You might be interested in

What are some renewable energy sources

liraira [26]

Wind, solar, biomass, hydropower

4 0

4 years ago

Read 2 more answers

How would you prepare 500 ml of the following solutions : Sodium succinate buffer (0.1 mol/dm3 pH 5.64)

Nana76 [90]

Answer:

8.10g of sodium succinate must be added and 247mL of 0.1M HCl adding enough water until make 500mL

Explanation:

Succinic acid has a pKa₂ of 5.63

To solve this question we must find the amount of sodium succinate and 0.1M HCl that we have to add using H-H equation:

pH = pKa + log [A-] / [HA]

5.64 = 5.63 + log [Na₂Succ.] / [HSucc⁺]

0.01 = log [Na₂Succ.] / [HSucc⁺]

1.0233 = [Na₂Succ.] / [HSucc⁺] (1)

As:

0.1M = [Na₂Succ.] + [HSucc⁺] (2)

Replacing (2) in (1):

1.0233 = 0.1M - [HSucc⁺] / [HSucc⁺]

1.0233[HSucc⁺] = 0.1M - [HSucc⁺]

2.033[HSucc⁺] = 0.1M

[HSucc⁺] = 0.0494M

[Na₂Succ] = 0.0506M

Both [Na₂Succ⁺] and [HSucc⁺] ions comes from the same sodium succinate we have to find the moles of sodium succinate in 500mL of 0.1M. Then, based on the reaction:

Na₂Succ + HCl → HSucc⁺ + Cl⁻

The moles of HCl added = Moles HSucc⁺ we need:

Moles Na₂Succ:

0.500L * (0.1mol/L) = 0.0500 moles

Mass -Molar mass sodium succinate: 162.05g/mol-:

0.0500mol * (162.05g/mol) = 8.10g of sodium succinate must be added

Moles HCl:

0.0494M * 0.500L = 0.0247 moles HCl * (1L / 0.1mol) = 0.247L =

And 247mL of 0.1M HCl adding enough water until make 500mL

7 0

3 years ago

A liquid at room temperature with high vapor pressure has:

Elanso [62]

It’s B because of the quest

8 0

3 years ago

How many grams of ice at -13 deg C must be added to 711 grams of water that is initially at a temperature of 87 deg C to produce

Basile [38]

Answer:

The answer to your question is m = 4.7 kg

Explanation:

Data

Ice Water

mass = ? mass = 711 g

T₁ = -13°C T₁ = 87°C

T₂ = 10°C T₂ = 10°C

Ch = 2090 J/kg°K Cw = 4180 J/kg°K

Process

1.- Convert temperature to kelvin

T₁ = 273 + (-13) = 260°K

T₁ water = 87 + 273 = 360 °K

T₂ = 10 + 273 = 283°K

2.- Write the equation of interchange of heat

- Heat lost = Heat absorbed

- mwCw(T₂ - T₁) = miCi(T₂ - T₁)

-Substitution

- 0.711(4180)(10 - 87) = m(2090)(10 - (-13))

- Simplification

228842.46 = 48070m

m = 228842.46/48070

-Result

m = 4.7 kg

4 0

4 years ago

Calculate the molar mass of cacl2

kirza4 [7]

Answer:

$\boxed {\boxed {\sf 110.98 \ g/mol}}$

Explanation:

The molar mass is the mass of a substance in grams per mole.

To find it, add the mass of each element in the compound. These masses can be found on the Periodic Table.

The compound given is:

$CaCl_2$

The compound has 1 Ca (calcium) and 2 Cl (chlorine).

Mass of Calcium

The molar mass of calcium is 40.08 g/mol
There is only one atom of Calcium in CaCl₂, so the number above is what we will use.

Mass of Chlorine

The molar mass of chlorine is 35.45 g/mol
There are two atoms of chlorine in CaCl₂, therefore we need to multiply the molar mass by 2.
35.45 * 2= 70.9 g/mol

Molar Mass of CaCl₂

Now, to find the molar mass, add the molar mass of 1 calcium and 2 chlorine.
40.08 g/mol + 70.9 g/mol =110.98 g/mol

The molar mass of CaCl₂ is 110.98 grams per mole.

6 0

3 years ago