Bài tập hiệu suất phản ứng - Hóa Học 10
Một hỗn hợp khí A gồm
N2 và H2 theo tỉ lệ số mol 1:3 tạo phản ứng cho ra NH3
sau phản ứng thu được khí B, tỉ khối hơi của A so với B là 0,6
a/Tính hiệu suất tổng
hợp NH3
b/Cho B qua nước thì
còn lại là hỗn hợp khí C. Tính tỉ khối hơi của A đối với C
giải:
gọi số mol của N2
là x, do tỉ lệ 1:3 nên số mol của H2 là 3x
N2 + 3H2
à2NH3
n…...3n……2n
như vậy theo phản ứng
trên sau khi đạt trạng thái cân bằng thì ta sẽ có:
x-n mol N2
; 3x-3n mol H2 và 2n mol NH3.
Đề cho tỉ khối hơi của
A so với B là 0,6, do A và B ở cùng điều kiện nên:
MA:MB=0,6
ó4x-2n=0,6.4x
ó0,4.4x=2n
ón:x=1,6:2=0,8
Vậy hiệu xuất là
80%..
b. khi cho B qua nước
thì NH3 mất đi. Nên trong C cũng có N2 và H2,
có tỉ lệ mol 1:3 như thằng A do đó tỉ khối hơi bằng 1.
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Facebook and Twitter are both taking action after a video shared by President Trump they say contains misinformation about the coronavirus
Facebook, apparently, does have a line.
The social media giant removed a video from Donald Trump's official Facebook page on Wednesday. The stated reason, according to a company spokesperson, was that the post spread misinformation about the coronavirus.
"This video includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misinformation," confirmed the spokesperson over email.
A visit to Trump's Facebook page shows no trace of the post. When asked if Facebook would put some sort of notice in place of the now-removed video — perhaps explaining why it was removed — the spokesperson replied that's not Facebook's policy.
"Don’t think we would put notice on content we remove, so in this case the post just comes down," they clarified.
In the removed video, the president told Fox & Friends that schools should remain open.
"My view is that schools should be open," Trump said. “If you look at children, children are almost — and I would almost say definitely — but almost immune from this disease.”
He added that children have "much stronger immune systems" and "just don't have a problem."
According to Facebook, this is the first time the social media platform has taken down a post from the president regarding misinformation about the coronavirus pandemic.
It was not immediately clear if all posts containing the video have been removed.
The move comes as Facebook CEO Mark Zuckerberg has faced increased scrutiny to crack down on misinformation since the 2016 election, with a long list of companies that have threatened to pull advertising on the platform.
The same clip was also shared by the Trump campaign's Twitter account - @teamtrump - and retweeted by the president himself.
A Twitter spokesperson told Fox News the tweet is "in violation of the Twitter rules on COVID-19 misinformation" and that the Trump campaign will "be required to remove the Tweet before they can Tweet again."
Trump campaign spokesperson Courtney Parella told Fox News that President Trump was "stating a fact that children are less susceptible to the coronavirus."
"Another day, another display of Silicon Valley’s flagrant bias against this President, where the rules are only enforced in one direction," she added. "Social media companies are not the arbiters of truth.”
Parella also claimed that the Twitter spokesperson who flagged campaign's suspended account was Kamala Harris' former press secretary.
A review of the latest available data by the Kasier Family Foundation found while there is already widespread community transmission in areas of the United States, there is "clearly a risk of further spread associated with reopening schools."
"The risks of reopening need to be considered carefully in light of the recognized benefits of in-person education," the foundation added.
The foundation noted there is "some evidence for an age gradient in infectiousness, with younger children less likely and older children more likely to transmit at levels similar to adults."
The National Academies of Medicine reported that “compared with adults, children who contract COVID-19 are more likely to experience asymptomatic infection or mild upper respiratory symptoms”, and that over 90 percent of children testing positive will have no or mild symptoms.
Children under the age of 18 account for 7%, or more than 200,000, of reported COVID-19 cases, according to the U.S. Centers for Disease Control and Prevention. They also account for 1% of coronavirus-related hospitalizations and less than 1% of coronavirus-related deaths.
According to Johns Hopkins University, there are more than 4.8 million coronavirus cases in the United States. More than 1.5 million Americans have recovered, while more than 157,000 Americans have died.
The social media giant removed a video from Donald Trump's official Facebook page on Wednesday. The stated reason, according to a company spokesperson, was that the post spread misinformation about the coronavirus.
"This video includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misinformation," confirmed the spokesperson over email.
A visit to Trump's Facebook page shows no trace of the post. When asked if Facebook would put some sort of notice in place of the now-removed video — perhaps explaining why it was removed — the spokesperson replied that's not Facebook's policy.
"Don’t think we would put notice on content we remove, so in this case the post just comes down," they clarified.
In the removed video, the president told Fox & Friends that schools should remain open.
"My view is that schools should be open," Trump said. “If you look at children, children are almost — and I would almost say definitely — but almost immune from this disease.”
He added that children have "much stronger immune systems" and "just don't have a problem."
According to Facebook, this is the first time the social media platform has taken down a post from the president regarding misinformation about the coronavirus pandemic.
It was not immediately clear if all posts containing the video have been removed.
The move comes as Facebook CEO Mark Zuckerberg has faced increased scrutiny to crack down on misinformation since the 2016 election, with a long list of companies that have threatened to pull advertising on the platform.
The same clip was also shared by the Trump campaign's Twitter account - @teamtrump - and retweeted by the president himself.
A Twitter spokesperson told Fox News the tweet is "in violation of the Twitter rules on COVID-19 misinformation" and that the Trump campaign will "be required to remove the Tweet before they can Tweet again."
Trump campaign spokesperson Courtney Parella told Fox News that President Trump was "stating a fact that children are less susceptible to the coronavirus."
"Another day, another display of Silicon Valley’s flagrant bias against this President, where the rules are only enforced in one direction," she added. "Social media companies are not the arbiters of truth.”
Parella also claimed that the Twitter spokesperson who flagged campaign's suspended account was Kamala Harris' former press secretary.
A review of the latest available data by the Kasier Family Foundation found while there is already widespread community transmission in areas of the United States, there is "clearly a risk of further spread associated with reopening schools."
"The risks of reopening need to be considered carefully in light of the recognized benefits of in-person education," the foundation added.
The foundation noted there is "some evidence for an age gradient in infectiousness, with younger children less likely and older children more likely to transmit at levels similar to adults."
The National Academies of Medicine reported that “compared with adults, children who contract COVID-19 are more likely to experience asymptomatic infection or mild upper respiratory symptoms”, and that over 90 percent of children testing positive will have no or mild symptoms.
Children under the age of 18 account for 7%, or more than 200,000, of reported COVID-19 cases, according to the U.S. Centers for Disease Control and Prevention. They also account for 1% of coronavirus-related hospitalizations and less than 1% of coronavirus-related deaths.
According to Johns Hopkins University, there are more than 4.8 million coronavirus cases in the United States. More than 1.5 million Americans have recovered, while more than 157,000 Americans have died.
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MSNBC’s Rachel Maddow says Trump 'was just spitballing'
MSNBC’s Rachel Maddow accused President Trump of making up and “just spitballing” that the massive explosion that rocked the Lebanese capital of Beirut earlier in the day was likely an attack caused by a bomb.
“Here’s a thing that should never, ever, ever, ever, ever happen from the White House,” Maddow said.
“Not only should this never happen from the White House, it should never happen anywhere anyone is in any position of supposed authority,” she continued. “What happened today shouldn’t happen from a White House podium, but it also like shouldn’t happen from a teacher’s desk. It shouldn’t happen from the voice of a cop giving you a parking ticket. It shouldn’t happen from a PA announcement at a supermarket about which car has its lights on in the parking lot. This shouldn’t come from anybody who purports to be giving you actual information from any position of purported authority.”
Maddow then played a clip of Trump speaking on Tuesday, when he said U.S. military generals have informed him that the explosion was likely caused by a bomb.
Maddow accused Trump of “just winging it” and “making it up as he goes along” by speculating the explosion was an attack.
“It looks like a terrible attack? What? It was an attack, said the president?” a perplexed Maddow said. “To be clear, before the president said that today from the White House, there had been no public indication at all that this was an attack, that this was some sort of terrorist or military assaults on the city of Beirut.”
Maddow appeared to grow more and more peeved as she continued.
nam
“When the president of the United States speaking from the White House podium says, ‘This is an attack,’ that’s a huge piece of news. That’s a huge deal. That’s like announcing the start of a war, kind of news, from the mouth of the president of the United States,” Maddow said.
“Except with this president, nah, turns out, eh grain of salt, he makes stuff up. He didn’t know if it was an attack, even when he was saying it’s an attack. He didn’t know. He was just spitballing,” she said.
Maddow then said Trump simply makes things up and blurts them out, calling his comments “absolutely atrocious.”
As for spitballing, Maddow famously devoted her program to speculation about whether or not Trump's campaign colluded with Russia until the findings from former Special Counsel Robert Mueller debunked her nightly narrative in 2019.
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