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4 years ago

1. Which one is the odd one out? 0 CaO o Cu o CO o CH

Chemistry

1 answer:

Sauron [17]4 years ago

4 0

Answer:

Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds, famous for displaying high-temperature superconductivity.It includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen (77 K) at about 92 K.Many YBCO compounds have the general formula Y Ba 2 Cu 3 O 7−x (also known as Y123),

Explanation:

i hope this makes sense and helps man

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Use the unbalanced equation NH3 + O2 = NO + H2O

Elodia [21]

<span>The balance format is
4NH3+ 5O2 -------> 4NO + 6H2O </span>

7 0

3 years ago

Table salt is sodium chloride and has the chemical formula of NaCl. What is the ratio of sodium atoms to chlorine atoms? (8.5D)

astra-53 [7]

Answer:

Explanation:Table salt is sodium chloride and has the chemical formula of NaCl. What is the ratio of sodium atoms to chlorine atoms? (8.5D)

Answer

А 2:1

1:1

1:2

3:1

7 0

3 years ago

I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19

IRINA_888 [86]

Answer:

A) Sample B has more calcium carbonate molecules

Explanation:

M = Molar mass of calcium carbonate = 100.0869 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

For the 4.12 g sample

Moles of a substance is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}$

Number of molecules is given by

$nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}$

For the 19.37 g sample

$n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}$

Number of molecules is given by

$nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}$

$1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}$

So, sample B has more calcium carbonate molecules.

The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.

7 0

3 years ago

A sample of a substance has a mass of 7.5 g and a volume of 2.5 cubic centimeters. What is the object’s density?

Inga [223]

Answer:

option A is the correct answer .

Explanation:

as density = mass per unit volume

density = 7.5/2.5 = 3 gm / cm³ ..is the answer ...

pls mark my answer as brainlist plzzzz and plz vote